GRADE 3 REVIEW NOTES
(DESCIBING MATTER)
©PROPERTIES OF MATTER DEFINITION
Matter is anything that has weight and takes up space. Everything you can see and touch is made up
of matter. Matter exists in three main forms: solids, liquids, and gases. It also has properties that we
can describe through density, solubility, conductivity, magnetism, etc.
LET’S BREAK IT DOWN!
When scientists use the word “matter” they are talking about solids, liquids, and gases.
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Matter can be found on Earth in three main forms: solids, liquids, and gases. Solids are materials
that have a defined shape and volume that stays the same. Rocks are a good example of a solid they have a rigid shape that isn’t easily changed.
Liquids are a type of matter that changes shape depending on the shape of its container. For
example, when you pour milk into a cup, it takes up the cup’s inner shape.
Matter that spreads out to take up all the space available in the container is called a gas. Air is a
gas. So is helium, which is put inside birthday party balloons.
Matter can be identified through its properties.
testing the properties of two metals using a magnet
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One clue to helps us identify matter is magnetism.
Magnetism is the ability of a material to be attracted by a magnet. Only certain materials are
attracted to magnets, like iron, nickel, and cobalt.
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Another property that can help us identify matter is solubility.
Solubility describes how well a substance can be dissolved. Some substances, like salt, are
easily dissolved by water but not easily dissolved by other liquids, like acetone.
Acetone is a chemical found in nail polish remover. Acetone does a great job dissolving nail polish,
but it cannot dissolve salt.
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Density is an important property of matter.
two balloons with different densities, one rises and the other sinks
 An object’s density depends on how closely the tiny particles are packed together. Objects with
a high density have particles that are more tightly packed than objects with a low density.
To better understand density, you can think about the difference between a golf ball and a ping-pong
ball. Even though they are about the same size, golf balls are heavier because they have a higher
density.
How something floats or sinks is also related to its density. In the video, one balloon was filled with
helium and the other was filled with sulfur hexafluoride. The helium balloon went up because its
density is less than air. The balloon with sulfur hexafluoride sank because its density is greater than
air.
Knowing the properties of matter can help you pick the right materials for the job.
 Styrofoam is dissolved in acetone in a scientific demonstration about solubility
 If you are going on a canoe trip and want to take along some cold sodas, taking a Styrofoam
cooler would be a good choice of materials. Styrofoam is not dissolved by water and is a good
insulator. However, if you wanted to store some acetone for a science project, a Styrofoam
container would not be a good choice. Acetone easily dissolves Styrofoam, meaning it would
melt through.
 If you are making a rocket engine, it might seem like a good idea to make it out of aluminum
because it is a light metal, however aluminum would also melt from the rocket's heat. In this
case, you might want to choose ceramic (same thing pottery is made of) because it has better
properties (withstands heat).
Science Terminologies

Acid
Any water-soluble compound having a sour taste and capable of turning litmus red and
reacting with a base to form a salt. Acid has a pH-level of less than 7.0 (A pH of 7 is neutral).
 Acid rain
Rain which is unusually acidic (pH of less than the natural range of 5 to 6), caused mainly by
atmospheric pollution with sulphur dioxide and nitrogen compounds.
 Air
A mixture of gases (especially oxygen) required for breathing; the stuff that the atmosphere
consists of.
 Air pressure (Atmospheric pressure)
Air pressure is the weight of the atmosphere pressing down on the earth. It is measured by a
barometer in units called millibars.
 Albert Einstein
Albert Einstein (14 March 1879 – 18 April 1955) was born in Germany and was a Jewish
philosopher and author, who is widely regarded as one of the most influential and best known
scientists and intellectuals of all time.
In 1933, he joined the Institute for Advanced Study in Princeton, New Jersey and lived and
worked there until his death. Einstein is probably familiar to most people for his mathematical
equation about the nature of energy, E = MC2.
 Altitude
The height above sea level or above the earth’s surface.
 Ambergris
A sperm whale secretion. Sperm whales produce it to protect their stomachs from the beaks of the
cuttlefish they swallow, and formerly valued greatly in the manufacturing process of perfumes.
 Ambient Temperature
The temperature of the surrounding air.
 Amplifier
An electronic device that changes, usually increases, the strength or amplitude of a signal passing
through it.
 Amplify
To increase the volume of or ‘amplify’ sound.
 Anemometer
An anemometer is a meteorological instrument that measures wind speed, either be gauging
velocity or pressure.
 Astrolabe
An ancient circular instrument used to observe and calculate the position of celestial bodies.
 Atmosphere
The gases surrounding the Earth or any astronomical body of sufficient mass, held together by the
gravity of the body.
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Atoms
The smallest component of an element or ‘matter’ having the chemical properties of the element.
 Bacteria
Very small living organisms made of only one cell which are present everywhere (the air, the soil,
on the skin). Many types of bacteria can cause diseases, but others can be very helpful to humans.
 Balance
A state of equilibrium
 Balance point
The point along the length of the shaft at which it will balance itself when placed on a fulcrum.
 Barometer
An instrument for measuring atmospheric pressure, used especially in weather forecasting, but is
also used to measure altitude.
 Benjamin Franklin
Benjamin Franklin, (January 17, 1706 – April 17, 1790) was one of the Founding Fathers of the
United States of America. Franklin was a leading author and printer, satirist, political theorist,
politician, scientist, inventor, civic activist, statesman, and diplomat.
As a scientist, he was a major figure in the Enlightenment and the history of physics for his
discoveries and theories regarding electricity.
 Berlese funnel
A device in which soil is placed; heat and light are applied from above, forcing bugs into a
container below it. Named after Antonio Berlese an Italian entomologist.
 Bernoulli’s principle
The principle of conservation of energy applied to fluid flow: as the speed of a moving fluid
increases, the air pressure within the fluid decreases. Named after Daniel Bernoulli, a Swiss
mathematician and scientist, Bernoulli is famous for his work in the field of fluid dynamics.
In 1738 he wrote a book called Hydrodynamica. In this book he explained his theories about how
gases and fluids move, and how the speed at which they move affects the pressure they exert on
objects they flow around.
 Biceps
The biceps of a human is a muscle located on the upper arm. The biceps has several functions,
the most important being to rotate the forearm and to flex the elbow.
 Big dipper
A group of seven bright stars in the northern sky, near the pole – also called the constellation Ursa
Major or the Great Bear.
 Binary code
Electronic data used in computers. The circuit is either on or off and is represented with either a 1
or 0. The system uses the digits 0 and 1 to represent a letter, numeral or other character in a
computer.
 Binaural hearing
The perception of sound by stimulation of two ears affecting a listener’s ability to identify the
location or origin of a detected sound in direction and distance.
 Biosphere
A ‘biosphere’, also called an ‘ecospheres’, is a mostly closed ecosystem of a specific size that
contains a mix of plants and animals that is completely self-sufficient.
 Block and tackle
A block and tackle is a compound pulley where several pulleys are mounted on each axle, further
increasing the mechanical advantage.
 Buoyancy
The ability of water to support weight allowing an object to float.
 Buzzer
An electrical mechanism that produces an intermittent current and an audible buzzing sound, or
series of sounds, when electrical current flows through it.
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Calcium
A mineral salt that strengthens the bones.
 Calcium carbonate
Calcium carbonate (CaCO3) is a common substance found in rock in all parts of the world, and
is the main component of shells of marine organisms like snails, pearls, seashells and corals.
Saltwater reef tank keepers have to dose or supplement this compound in order for corals to
grow. Corals need calcium carbonate to grow.
 Capacitor
A capacitor is an electrical component used to control the flow of charge in a circuit. The name
derives from their capacity to store an electric charge. Capacitors consist of two conducting surfaces
separated by an insulator; a wire lead is connected to each surface.
A capacitor can store electric energy and discharge it at a determined rate.
 Capillary action
The flow of liquids through porous media, such as the flow of water through blotting paper.
 Caramel
Made by cooking sugar slowly, used in candy making and sweetening of foods
 Carbon dioxide
Carbon dioxide is a colourless, odourless incombustible gas present in the atmosphere. It is
formed during the breathing of living organisms, the decomposition and combustion of organic
compounds, and in the reaction of acids with carbonates: used in fizzy drinks, fire extinguishers, and
as dry ice for refrigeration.
 Carcinogenic
A carcinogenic substance is any substance that produces cancer or stimulates the production of
cancerous cells.
 Catalyst
A substance that initiates or accelerates a chemical reaction without itself being affected
 Celestial bodies
Objects that are naturally occurring physical entities or structures, that current science has
demonstrated to exist in outer space.
 Cells
The basic structural and functional unit of all living organisms. Cells can exist as independent units
of life (as in monads) or may form colonies or tissues as in higher plants, animals or human beings.
 Centrifugal force
Centrifugal force is the effect that tends to move an object away from the centre of a circle it is
rotating about (a consequence of inertia).
 Chemical element
Any of the more than 100 known substances that cannot be separated into simpler substances
and that individually or in combination constitute all matter.
 Chemical indicator
Any substance used to classify another, often by changing colour.
 Chemical reaction
The formation of new substances from one or more reactants, by breaking existing electrical
bonds and creating others.
 Chlorophyll
A green-coloured compound or ‘pigment’ in plants that converts radiant energy to chemical energy
through the process of photosynthesis.
 Chromatography
An analytical chemistry technique for separating and identifying mixtures that are or can be
coloured, especially pigments.
 Cobalt chloride
A chemical substance often used to predict the presence of water molecules within the air or other
substance.
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Climacteric fruit
The climacteric is a stage of fruit ripening associated with ethylene production and cell
respiration rise. Apples, bananas, melons, apricots, tomatoes (among others) are climacteric fruit.
Citrus, grapes, strawberries are non-climacteric (they ripen without ethylene and respiration bursts).
 Cocoon
The silky protective case spun by the larvae of some insects and moths in which they
metamorphose.
 Cohesion
Cohesion is a physical property of a substance, caused by the intermolecular attraction between
like-molecules within a body or substance that acts to unite them.
 Colour spectrum
The distribution of colours produced when light is dispersed by a prism. The order is displayed in
the following order: Red, Orange, Yellow, Green, Blue and Violet.
 Condensate
The opposite of ‘evaporate’. The transition from a gaseous state into a liquid state.
 Condensation
Condensation is the process by which matter transitions from a gas (or vapour) phase into a liquid
phase. Dew forming on grass in the morning is a common example of condensation.
 Conduction
The movement of heat through a material as kinetic energy is transferred from molecule to
molecule. The handle of an iron pan on the stove gets hot due to heat conduction.
 Conductor
A material that has enough free electrons to allow an electrical current to flow when a potential
difference is applied. Conductors are usually metallic in nature, but not always, such as graphite for
example.
 Convection
The transfer of heat through a fluid (liquid or gas) caused by molecular motion. In the atmosphere,
convection usually refers to the vertical movement of air masses. An example of convection is the
rising of warm surface air and the sinking of cold air from upper levels of the atmosphere.
 Convex / Concave
Curving or bulging outward or inward.
 Creep
Creep is the tendency of a solid material such as soil, to slowly move or deform permanently
under the influence of certain forces.
 Dehydration
Dryness resulting from the removal of water.
 Density
The amount of matter contained by a given volume. The symbol of density is ρ (the Greek letter rho)
 Desiccant
A substance that promotes drying.
 Detergent
A detergent is a material intended to assist cleaning. The term is sometimes used to differentiate
between soap and other surface-active chemical cleaning agents widely used in industry and
laundering.
 Dew point
The temperature at which the water vapour in the air becomes saturated and condensation
begins. Dewpoint is expressed as a temperature in degrees Fahrenheit or Celsius.
 Dextrin
Dextrin is obtained by hydrolysis of starch. It is a tasteless, odourless gummy substance that is
often used as a thickening agent, in adhesives and in dietary supplements.
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Diffusion
The process by which a substance moves from an area of high concentration, through a barrier or
membrane, to an area of lower concentration.
 Diopter
A unit of measurement of the refractive power of a lens, which is equal to the reciprocal of the
focal length measured in meters.
 Displacement
Displacement occurs when an object is immersed in a fluid, pushing it out of the way and taking its
place.
 Dissolving
Solid matter reduced to a liquid form that has been disintegrated in a solvent.
 DNA
Deoxyribonucleic acid is a long linear polymer found in the nucleus of a cell and formed from
nucleotides and shaped like a double helix. DNA is associated with the transmission of genetic
information or all living organisms and some viruses.
 Dominant eye
Also known as Ocular dominance is the tendency to prefer visual input from one eye to the other.
It is somewhat similar to being right or left handed. The side of the dominant eye and the dominant
hand do not always match.
 Downforce
The downward pressure created by the aerodynamic characteristics of a car that allows it to travel
faster through a corner by increasing the pressure between the contact area of the tire and the road
surface, thus creating more grip.
 Dye
A usually soluble substance for staining or colouring e.g. fabrics or hair.
 Echo
The repetition of a sound resulting from reflection of the sound waves.
 Echo-location
Determining the location of something by measuring the time it takes for an echo to return from it.
 Echo-sounding
Determining the location of something by measuring the time it takes for an echo to return from it.
 Eclipse
An eclipse is an astronomical event that occurs when one celestial object moves into the shadow
of another.
 Eddy-current
Circulating movement of electrical current within an electrical conductor caused by the intersection
of the conductor with a moving magnetic field.
 Elastic energy
Potential energy that is stored when a body is deformed as in a coiled spring or elastic band
 Elastomer
Any polymer having the elastic properties of rubber.
 Electric generator
A device that converts mechanical or kinetic energy to electrical energy. The reverse conversion of
electrical energy into mechanical energy is done by a motor; motors and generators have many
similarities.
 Electric meter
A device that measures the amount of electrical energy consumed by a residence, business, or an
electrically powered device.
 Electrical current
Electrical current is the flow of charged electrons through a circuit. Electrical current, which is
electrons flowing in a wire, can be explained as cars driving along a road, where the road is the wire
and the cars are the electrons. The current would be the number of cars passing a given point.
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Electrolysis
The process by which we generate hydrogen and oxygen from water is called electrolysis.
 Electrolyte
An electrolyte is any liquid that is able to conduct electricity. Salt water makes an excellent
conductor.
 Electromagnet
An electromagnet is a type of magnet whose magnetic field is produced by the flow of electric
current. The magnetic field disappears when the current ceases.
 Electrons
Tiny particles with a negative charge that are capable of creating an electrical current.
 Electroplating
The deposition of a metal coating onto an object by putting a negative charge on it and putting it
into a solution which contains a metal salt. The metal salt contains positively charged metal ions
which are attracted to the negatively charged object and are “reduced” to metallic form upon it.
 Electroscope
A simple device that detects the presence of an electric charge by the mutual repulsion of metal foils.
 Elodea
Elodea is a type of aquatic plant often called the waterweeds. Elodea is native to North America
and is also widely used as aquarium vegetation.
 Embryo
A minute rudimentary plant contained within a seed.
 Endothermic reaction
A chemical reaction accompanied by the absorption of heat.
 Entropy
The amount of order or disorder present in a thermodynamic system. Entropy measures how
ordered the molecules of a substance are arranged and hence determines whether a material
expands or contracts when heated.
 Enzyme
Complex proteins produced by cells that facilitates or speeds up certain bio-chemical reactions in
the body.
 Ethylene
Ethylene is an organic gas compound with the formula C2H4. This gas is produced by fruits and
vegetables that is rotting and accelerates the ripening and aging process of nearby fruits.
 Eutrophication
A process by which an excess of plant nutrients, for example nitrogen and phosphorous, reduces
the oxygen dissolved within a body of water, producing an environment that does not readily support
aquatic life.
 Evaporate
The opposite of ‘condensate’. The transition from a liquid state into a gaseous state.
 Evaporation
The process of a liquid converting to the gaseous state. Evaporation is a type of vaporization of a
liquid, which occurs only on the surface of a liquid.
 Exothermic reaction
A chemical reaction in which heat is given off during the formation of new chemical compounds.
 Fat
A soft greasy substance occurring in organic tissue and consisting of a mixture of lipids.
 Filament
A thin wire in a light bulb that is heated white hot by the passage of an electric current. Tungsten is
often used.
 Fingerprint
An impression of the underside of the end of a finger or thumb. It is used for identification because
the arrangement of ridges in any fingerprint is thought to be unique and permanent with each person.

Fire extinguisher
Any of various portable steel container devices for spraying and extinguishing a fire with Carbon
dioxide or other chemicals.
 Float
To be afloat either on or below a liquid surface and not sink to the bottom of the liquid.
 Fluid
A fluid is a substance that continually deforms or ‘flows’. All gases and most liquids are considered
to be fluids. The main characteristic of a fluid is that they are capable of flowing and easily changing
shape.
 Freezing point
The temperature at which a liquid changes state and forms a solid.
 Friction
The interaction between surfaces: a measure of the resistance felt when sliding one body over
another.
 Fulcrum
The pivot about which a lever turns
 Fungus
An organism of the kingdom ‘Fungi’ lacking chlorophyll and feeding on organic matter.
 Fuse
Also called a ‘fusible link’ is a type of over current protection device. It consists of a metal wire or
strip that melts when too much current flows, which interrupts the circuit in which it is connected.
 Galileo
Galileo Galilei was an Italian astronomer and mathematician who was the first to use a telescope
to study the stars; demonstrated that different weights descend at the same rate; perfected the
refracting telescope that enabled him to make many discoveries (1564-1642).
 Galvanometer
A type of ammeter or instrument for detecting or comparing or measuring small electric currents.
 Gear
A toothed wheel that engages another toothed mechanism in order to change the speed or
direction of transmitted motion.
 Genetically engineered plants
The alteration of the genome of plants grown for food in order to produce crops with specific
advantages.
 Germination
The process whereby seeds or spores sprout and begin to grow
 Grafting
A method of plant breeding widely used in agriculture and horticulture, where the tissues of one
plant are encouraged to fuse with those of another.
 Gravity
The force of attraction between all masses in the universe, especially the attraction of the earth’s
mass for bodies near its surface. The farther a body from the earth’s surface, the less the
gravitational force acting on it.
 Grounding
The process of connecting equipment to a common ground or ‘earth’. This is done as a safety
mechanism in order to avoid the unsafe energizing of equipment.
 Heat
A form of energy that is transferred by a difference in temperature.
 Helium
Helium is the chemical element with atomic number 2 and an atomic weight of 4.0026, which is
represented by the symbol He. Helium is a colourless, odourless and tasteless gas. It also makes up
a small amount of the air we breathe. It originates from the Greek word ‘helios’ meaning the sun.
Helium is commonly used as a cooling agent in superconductors, cryogenics, inflating balloons as
well as inflating airships.
 Hering Illusion
This is an optical illusion named by Ewald Hering. The vertical or horizontal lines are all straight,
but look as if they were bent. The distortion is produced by a lined pattern on the background that
simulates a perspective design and creates a false impression of depth..
 Hormone
A chemical substance produced in a living organism which controls the rate of biochemical
processes.
 Horticulture
The science of caring for gardens or gardening; small scale agriculture.
 Hot-air balloon
Balloon for travel through the air in a basket suspended below a large bag or ‘envelope’ of heated air.
 Humidity
The relative humidity is a measure of the amount of water vapour in the air (at a specific
temperature) compared to the maximum amount of water vapour air could hold at that temperature,
and is given as a percentage value.
 Hydroelectric power
Hydroelectric power is electricity generated by hydropower, i.e., the production of electrical power
through the use of the gravitational force of falling or flowing water.
 Hydrogen peroxide
An almost colourless, slightly pale blue liquid. H2O2 is soluble in water. Hydrogen peroxide is
used as a mild antiseptic and is often found in bleaching agents, especially for bleaching hair.
 Hydroponics
A technique of growing plants (without soil) in water containing dissolved nutrients.
 Hygrometer
Measuring instrument for measuring the relative humidity of the atmosphere.
 Ice
Water frozen in the solid state.
 Igneous rocks
Rocks that are produced under conditions involving intense heat.
 Immiscible
The chemical property where two or more liquids or phases do not readily mix or dissolve in one
another, such as oil and water.
 Immiscible liquids
Immiscibility is two or more liquids that are not mutually soluble or un-mixable, whereas miscibility
is the property of liquids to mix in all proportions, forming a homogeneous solution.
 In Parallel
Connected at the same time. Electrical components connected side by side, instead of in series.
 Inclinometer
A measuring instrument for measuring the angle of magnetic dip. Airplane pilots make use of this
device to show the angle that an aircraft makes with the horizon.
 Indicator
Any substance used to classify another, often by changing colour.
 Induction
An electrical phenomenon whereby an electrical current is generated in a closed circuit, by a
stroking a magnet along a conductor.
 Inertia
The tendency of a body to maintain its state of rest or uniform motion unless acted upon by an
external force.
 Insulator
A material such as glass or porcelain with a very tiny electrical or thermal conductivity.

Infra-red rays
Invisible radiation in the part of the electromagnetic spectrum characterized by wavelengths just
longer than those of ordinary visible red light and shorter than those of microwaves or radio waves.
 Integrated circuit
A collection of active and passive electrical components such as transistors and resistors mounted
on a single slice of silicon and packaged as a single component. An integrated circuit is also known
as an IC, microcircuit, or microchip.
 Invisible ink
A substance used for writing, which is invisible either on application or soon thereafter, and which
can later on be made visible by some means.
 Iodine
A non-metallic element belonging to the halogens. Iodine is used especially in medicine and
photography and in dyes. It occurs naturally only in combination in small quantities as in sea water or
rocks.
 Iris
A muscular diaphragm that controls the size of the pupil which in turn controls the amount of light
that enters the eye. The iris forms the coloured portion of the eye.
 Isaac Newton
Sir Isaac Newton (1642-1727), a mathematician and physicist were of the foremost scientific
intellects of all time and who is famous for his ‘action-reaction law’ which states: ‘to every action there
is an equal and opposite reaction’.
 Jean Foucault
Jean Bernard Léon Foucault (18 September 1819 – 11 February 1868) was a French physicist
best known for the invention of the Foucault pendulum, a device demonstrating the effect of the
Earth’s rotation.
 Kaleidoscope
A tubular instrument containing loose bits of coloured glass, plastic, etc. reflected by mirrors so
that various symmetrical patterns appear when the tube is held to the eye and is rotated
 Kazoo
A toy wind instrument that has a membrane that makes a sound when you hum into the
mouthpiece.
 Kilowatt hour
A kilowatt-hour (kWh) is a standard metric unit of measurement for electricity consumption for
billing purposes. It can simply be described as 1000 watts of electricity used for one hour.
 Kinetic energy
The energy possessed by an object by virtue of its motion is called kinetic energy. The greater the
mass or speed of the object, the greater is the kinetic energy. Kinetic means active or moving.
Kinetic energy can be defined as energy in motion or the energy of a moving object.
 Landslide
A rapid down slope mass movement where water in the soil and rock has accumulated to
sufficiently increase stress and lubricate bedding planes.
 LED
A type of a semi-conductor or ‘solid state’ light source. LED’s can produce a very bright light for a
small amount of power.
LED’s are now used in many applications, for example car brake lights and traffic lights, although
white coloured LEDs are still a relatively new technology.
 Lever
A rigid bar used to apply pressure at one point along its length by applying a force (effort) at a
second point and turning about a third point or fulcrum.
 Lignum
Wooden tissue. This may or may not contain the bark of the tree as well.

Lift
A fluid flowing past the surface of a body exerts a surface force on it. Lift is defined to be the
component of this force that is perpendicular to the oncoming flow direction. Lift Take off or away by
decreasing the air pressure.
 Litmus
A colouring material (obtained from lichens, a composite organism consisting of fungi) that turns
red in acid solutions and blue in alkaline solutions. It is used as a very rough acid-base indicator.
 Little dipper
A cluster of seven stars in the constellation Ursa Minor also called Little Bear. At the end of the
dipper’s handle is ‘Polaris’, the North Star.
 Lumens
The SI unit of luminous flux. It is a measure of the power of light that can be perceived by the
human eye.
 Lunar month
The average time between successive new or full moons. A lunar month is equal to 29 days 12
hours 44 minutes. Also called a ‘synodic’ month.
 Machine
Any mechanical or electrical device that transmits or modifies energy to perform or assist in the
performance of human tasks. Also, a device that has parts to perform or assist in performing any type
of work.
 Magnetic field
A condition in the space around a magnet or electric current in which there is a detectable
magnetic force and two magnetic poles are present.
 Magnetic North
North according to the Earth’s magnetic poles rather than its geographic poles. Declination from
true north is given in miles where one mile equals 1/6,400 of 360 degrees.
 Magnetism
The force of attraction or repulsion of a magnetic material due to the arrangement of its atom. A
magnet is a metal object that attracts pieces of ferrous (metal) objects.
 Magnification
A measurable increase in the apparent size of an object. This enlargement is quantified by a
calculated number also called ‘magnification’. Magnification is the ratio between the apparent size
and the true size of the viewed object behind the lens or other magnifier.
 Male ants
Male ants do not work and live only a few weeks or months. The only purpose of the male ant is to
mate with the queens and they die shortly thereafter.
 Maltose
A white crystalline sugar formed during the digestion of starches.
 Mantle
Earth’s mantle is a rocky shell about 2,890 km thick that constitutes about 84 percent of Earth’s
volume. It is predominantly solid and encloses the iron-rich hot core, which occupies about 15 percent
of Earth’s volume.
 Matter
Matter is a general term for the “stuff” of which the world is made.
 Mealworms
Mealworms are the larva form of the mealworm beetle, ‘Tenebrio molitor’, a species of darkling
beetle. Like all holo-metabolic insects, they go through four life-stages: egg, larva, pupa, and adult.
Mealworms are a tasty treat for hamsters.
 Membrane
A pliable sheet of tissue that covers or lines or connects the organs or cells of animals or plants.

Meniscus
The curved top of a column of liquid, such as ‘water’ in a small tube. It is formed because the
attractive forces between the tube and the water molecules (adhesive forces) are stronger than the
cohesive forces between individual water molecules.
 Metabolism
The chemical reactions that allow organisms to grow and reproduce, maintain their structures, and
respond to their environments. Metabolism is usually synonymous with energy production.
 Metals
Any of several chemical elements that are usually shiny solids that conduct heat or electricity and
can be formed into sheets. Most metals also have magnetic properties.
 Metamorphic rock
Rocks formed from other rocks under pressure and extreme heat.
 Microbes
Minute living organisms, including but not limited to bacteria, viruses and fungi.
 Michael Faraday
Michael Faraday was a British physicist and chemist, best known for his discoveries of
electromagnetic induction and of the laws of electrolysis. While working for a bookbinder in London,
he read many scientific books and experimented with electricity.
Faraday’s most important scientific contributions were in the fields of electricity and magnetism. In
1821 Faraday plotted the magnetic field around a conductor carrying an electric current, and in 1831
he followed this accomplishment with the discovery of electromagnetic induction.
 Milliammeter
A sensitive ammeter for detecting small currents, graduated in milliamperes.
 Mold
A fungus that produces a superficial growth on various kinds of damp or decaying organic matter.
 Momentum
Momentum is the product of the mass and velocity (speed) of an object (p = mv).
 Mummification
The preserving of a dead body, by making it into a mummy.
 Mycology
The branch of living sciences concerned with the study of fungi.
 Natron
Natron is a natural salt, composed of sodium carbonate and sodium bicarbonate with traces of
sodium chloride and sodium sulphate. It was used by the ancient Egyptians to dry out the bodies
during mummification.
 Nocturnal
Animals or insects that is active during the night and sleep during the day.
 Non-ferrous metals
Non-ferrous metals are those that have very little iron content. Non-ferrous metals are nonmagnetic metals such as gold, silver or aluminium.
 Ohm’s law
Ohm’s law states that the current through a conductor between two points is directly proportional
to the potential difference or voltage across the two points, and in reverse proportional to the
resistance between them.
 Oil
Any of a group of fats that is a liquid at room temperature that are obtained from plants.
 Optic nerve
The optic nerve transmits visual information from the retina to the brain.
 Optical illusion
An optical phenomenon that results in a false or deceptive visual impression.
 Optician
A specialist in fitting eyeglasses and making lenses to correct vision.
 Oscillator
A tuned electronic circuit used to generate a continuous output repetitive variation, typically in time.
 Oscilloscope
An electronic device with a screen, which displays a picture of the voltage of an electrical signal.
When this device is connected to the output of an audio amplifier, it displays patterns related to the
sound pressure coming out of the loudspeaker.
 Osmosis
Osmosis is the diffusion of a liquid through a cell wall or membrane. Osmosis is the means by
which water and nutrients move.
 Oxidation
The addition of oxygen to a compound accompanied with a loss of electrons
 Oxygen
Oxygen, scientifically known as O2, occupies about 21 percent of the earth’s atmosphere and is
also found in other substances including water. It can combine with many other elements and it is
essential for plants & animals to breathe. Oxygen is also required for nearly all combustion.
 Pangaea
A hypothetical continent including all the landmass of the earth prior to the Triassic period when it
split into Laurasia and Gondwanaland.
 Partial melting zone
The layer between the crust and the mantle of the earth. This layer consists of a molten rock
‘liquid’ with high viscosity and acts like a viscous ‘sea’ upon which the continents drift!
 Pascal’s principle
States that: Pressure applied to an enclosed fluid is transmitted undiminished to every part of the
fluid, as well as to the walls of the container.
 Pedestal
A base, a support or a foundation.
 Pendulum
A weight suspended from a pivot so it can swing freely.
 Perfume
A pleasant smell, scent or odoriferous particles emitted from a sweet-smelling substance.
 Periodic table
A tabular arrangement of the chemical elements according to atomic number as based on the
periodic law.
 Periscope
An instrument that has angled mirrors or prisms and allows objects not in the direct line of sight, to
be seen. It is often used on submarines and in the military.
 Permeability
A measure of the ability of a porous material such as the walls or membranes of cells to transmit
fluids.
 Persistence of vision
A visual phenomenon where an image is retained in the eye for a short period of time, creating an
illusion of continuous motion in film and video.
 Pheromones
A chemical substance secreted externally by some animals, especially insects, which influences
the physiology or behaviour of other animals or insects of the same species.
 Photosynthesis
The process that enables plants and some bacteria to capture the sun’s energy and turn it into
food and oxygen.
 Phototropism
The tendency of plans to move or grow towards light.
 Pigment
A substance whose presence in plant or animal tissues produces a characteristic colour.

Pitch
The property of sound that varies with variation in the frequency of vibration.
 Plastron
The plastron is the nearly flat part of the shell structure of a turtle or tortoise, what one would call
the belly
 Plateau
A plateau is also called a ‘high plain’ or ‘tableland’. It is an area of highland, usually consisting of
relatively flat terrain. A highly eroded plateau is called a dissected plateau.
 Polaris
The brightest star in Ursa Minor located at the end of the handle of the Little Dipper. The northern
axis of the earth points almost directly toward it making it the current northern pole star. Polaris has
gone by so many names in its past: North Star, Steering Star, Lodestar, Stella Mars and the Ship Star.
 Polymer
A long or larger molecule consisting of a chain or network of many repeating units, formed by
chemically bonding together many identical or similar small molecules called ‘monomers’.
 Porous
Full of tiny pores that allow fluids or gasses to pass through.
 Potassium iodide
A white crystalline salt used in making photographic emulsions and in iodized table salt.
Potassium iodide is an inorganic compound with formula KI.
 Potassium nitrate (Saltpetre)
KNO3 is a naturally occurring mineral source of nitrogen. Its common names include saltpetre or
nitrate of potash. It is used in the production of nitric acid, model rocket propellants, and several types
of fireworks.
 Potential energy
The energy possessed by an object because of its position (for instance with regards to
gravitational force or in an electric field), or its condition (for instance a stretched rubber band)
 Preservatives
A preservative is a natural or synthetic substance or chemical that is added to products such as
foods, pharmaceuticals, paints, biological samples, wood, etc. to prevent decomposition by bacterial
growth or by unwanted chemical changes.
 Pressure
The force applied to a unit area of surface often measured in pascals (SI unit) eg. “the
compressed gas exerts an increased pressure”. Pressure = Force / Area
 Prism
A transparent body of this form, often of glass and usually with triangular ends, used for
separating white light passed through it into a spectrum or for reflecting beams of light.
 Proprioception
The ability of living organisms to sense the position and location and orientation and movement of
the body and its parts.
 Propulsion
A force causing movement.
 Protein
Any of the ‘amino acids’ present in all living matter that are an essential food item.
 Protractor
An instrument for measuring or drawing angles on paper, usually a flat semicircular transparent
plastic sheet graduated in degrees
 Pulley system
A simple machine, consisting of a wheel with a groove in which a rope can run to change the
direction, or point of application of a force applied to the rope
 Pulse
The rhythmic contraction and expansion of the arteries with each beat of the heart.

PV (Photovoltaic) Panels
Man-made cells that are comprised of semiconductors, materials that are able to absorb light
energy, arranged in a panel form to produce electric power.
 Queen ants
The queen ant is the only ant that is capable of laying eggs and this is also her main role in an
ant colony. She is brought food and is cleaned by workers ants and they also tend to the eggs that
she lays. The queen ants do not make any decisions about the colony, the decisions are carried out
by the entire colony.
 Radiation
The act or process of radiating; the radiation of heat and light from a fire.
 Radio
An electronic receiver that detects and demodulates and amplifies transmitted signals.
 Rain gauge
An instrument meteorologists use to measure the amount of rainfall.
 Rainbow
An arc of coloured light in the sky caused by refraction of the sun’s rays by rain.
 Reflectivity
The fraction of radiant light that is reflected from a surface.
 Reflex
A reflex action, also known as a reflex, is an involuntary and nearly instantaneous movement in
response to a stimulus.
 Refracting telescope
A telescope in which a large biconvex lens causes light rays to converge to a focus, forming an
image magnified by a biconvex eyepiece. A telescope is a device used to magnify distant objects.
 Refraction
The change in direction of a propagating wave (light or sound) when passing from one medium
to another
 Relative humidity
This is the ratio of the amount of water in the air at a given temperature to the maximum
amount it could hold at that temperature. Relative humidity is expressed as a percentage.
 Relay
A mechanical relay is an electromechanical device that closes contacts to complete a circuit or
opens contacts to interrupt a circuit. A solid state relay is a switching device that completes or
interrupts a circuit electrically and has no moving parts.
 Resistance
A material’s opposition to the flow of electric current. Resistance is measured in ‘ohms’.
 Resonance
Sympathetic resonance is a harmonic phenomenon wherein a formerly passive string or
vibratory body responds to external vibrations to which it has a harmonic likeness.
 Respiration
Respiration (or just breathing) is defined as the transport of oxygen from the outside air to the
cells within tissues, and the transport of carbon dioxide in the opposite direction.
 Retina
A delicate, multilayered, light-sensitive membrane lining the inner eyeball and connected by
the optic nerve to the brain.
 Rheostat
An electrical resistor, with two terminals, whose resistance are continuously variable by moving
a knob or slider and correspondingly decrease or increase the current flowing.
 Richter scale
A logarithmic scale, invented in 1935 by United States geophysicist Charles Richter, for
representing the energy released by earthquakes. A figure of 2 or less is barely perceptible, whereas
an earthquake measuring over 5 may be destructive, and 8 or more is a major earthquake.

Rocket
A rocket is a vehicle or object which obtains thrust by ejecting a jet of fast moving fluid exhaust
from a rocket engine.
 Rotor
A rotating mechanism, consisting of an assembly of rotating airfoils, that extracts energy from a
fluid or air flow and converts it into useful work.
 Rust
A red or brown oxide coating on iron or steel caused by the action of oxygen and moisture.
Rusting is the common term for the ‘corrosion’ or the disintegration of a material into its constituent
atoms, due to chemical reactions with its surroundings.
 Saliva
Saliva, also known as spit, or slobber, is the watery substance produced in the mouths of
humans and most other animals by the salivary glands. The saliva moistens the mouth and starts the
digestion of starches in the mouth.
 Salivary gland
Any of three pairs of glands in the mouth and digestive system that secrete saliva for food digestion.
 Samuel Morse
Samuel Finley Breeze Morse was born in Charlestown, Mass. on 27th April 1791. He was a
professional artist, inventor of the electric telegraph and the originator of ‘Morse’ Code. Morse is
remembered for his Code, still used, and less for the invention that enabled it to be used, probably
since landline telegraphy eventually gave way to wireless telegraphy.
 Saturated
A ‘saturated’ solution is the most concentrated solution possible at a given temperature. The
solution is unable to dissolve still more of a specific substance.
 Scurvy
A deficiency of ‘Vitamin C’. Symptoms include nausea, weakness, loss of hair and teeth, and
eventual death. It is caused by a lack of fruits and vegetables in the diet. More sailors at sea died of
this than any other cause.
 Seismograph
A device that is used to accurately record the motion of the ground during an earthquake.
Semi-permeable
It allows certain things to pass through while blocking others.
 Shadow clock
An ancient time telling device consisting of a straight base with a raised crosspiece at one end,
which uses the length of the sun’s shadows because of its position, in relation to a specific location on
earth, to tell the time.
 Sheet erosion
Relatively even erosion of a layer of soil without channel formation and generally takes place
on sloping land.
 Short circuit
An unintentional contact between two points in an electric circuit that have a potential difference.
 Sidereal day
The exact time for one complete rotation of the earth relative to a particular star. A sidereal day
is about 4 minutes shorter than a mean solar day. Astronomers use sidereal time as a way to keep
track of the direction in which their telescopes need to be pointed to view any given star in the night
sky. A sidereal day is about 1436.07 minutes.
 Siphon
A tube running from the liquid in a container to a lower level outside the container so that
atmospheric pressure forces the liquid through the tube.
 Smoke
A hot vapour containing fine particles of carbon being produced by combustion

Snellen chart
A chart with letters and numbers in lines of decreasing size; used to test visual acuity
 Snow
Snow is a type of ‘rain’ within the earth’s atmosphere in the form of ‘crystal-like’ ice water,
consisting of many snowflakes that fall from clouds.
 Soap bubble
A soap bubble is a very thin film of soapy water that forms a sphere with a sparkling surface.
 Soil-burrowing insects
Insects or bugs that live in soil and come out at night when it is dark to consume plants.
 Solar
Relating to, or derived from the sun or utilizing the energies of the sun.
 Solar energy
Energy from the sun that is converted into thermal or electrical energy.
 Sonar
Ships and Submarines often use Sonar to communicate and find their way. Sonar stands for:
Sound Navigation & Ranging.
 SOS Signal
SOS (Save Our Souls) is the best known international distress signal. Everyone should be
familiar with SOS. The SOS signal can be transmitted by any method, visual or audio. The code for
SOS is 3 short, 3 long and 3 short signals. Pause. Repeat the signal.
 Sound conductor
A material helping to pass on sound waves.
 Sound resonance
Soundwaves hitting and bouncing back on the walls of a container in which it travels. The
soundwaves are reinforced or enriched by the added sound vibrations.
 Spectrum
The portion of the electromagnetic spectrum that is visible to the human eye. Electromagnetic
radiation in this range of wavelengths is called visible light or simply light. A typical human eye will
respond to wavelengths from about 390 to 750 nm.
 Speed of light
The speed at which light travels in a vacuum; the constancy and universality of the speed of
light is recognized by defining it to be exactly 299,792,458 meters per second. Einstein’s ‘Theory of
Relativity’ implies that nothing can go faster than the speed of light and only objects without mass can
travel at this speed.
 Sphere
A sphere is a perfectly round geometrical object in three-dimensional space, such as the shape
of a ball.
 Spores
A spore is a reproductive structure that is adapted for spreading and surviving for extended
periods of time in unfavourable conditions similar to a plant seed.
 Starch
Starch is a carbohydrate consisting of a large number of glucose units joined together. Food
rich in natural starch is potatoes, rice and bread
 Static electricity
Static electricity refers to the build up of electric charge on the surface of objects.
 Steganography
The art and science of writing hidden messages in such a way that no one, apart from the
sender and intended recipient can see or read it.
 Stereoscopic vision
The single perception of a slightly different image from each eye, resulting in depth perception.

Stethoscope
A stethoscope is a medical device that doctors use for listening to sounds inside the body like
breathing or a heartbeat.
 Stomata
Tiny pores on the underside of plant leaves. Carbon dioxide, oxygen and water enter and leave
the plant through these tiny pores.
 Submarine
A vessel that is capable of operating submerged under water or below the sea. Also called a
‘sub’ for short.
 Suet
Animal fat mixture. Woodpeckers are attracted to suet hung in bags from trees.
 Supercontinent
A supercontinent is a landmass comprising more than one continental core, or craton.
 Supersaturated
A solution that contains more than the maximum amount of solvent that can normally be
dissolved in a given amount of solvent at normal ambient temperature.
 Surface tension
A property of liquids in which the exposed surface tends to contract to the smallest possible
area, as in the formation of a meniscus. It is caused by unequal molecular cohesive forces near the
surface.
 Sympathetic resonance
Sympathetic resonance is a harmonic phenomenon wherein a formerly passive string or
vibratory body responds to external vibrations to which it has a harmonic likeness.
 Taste buds
Taste buds are receptors for taste. They are located around the upper surface of the tongue,
soft palate, and throat.
 Temperature
Temperature is the measure of the average kinetic energy of the particles in a substance,
which is related to how hot or cold that substance is.
 Terminal velocity
An object is moving at its terminal velocity if its speed is constant due to the restraining force
exerted by the air, water or other fluid through which it is moving.
 Theory of Relativity
Einstein’s ‘Theory of Relativity’ is seen as one of the most important scientific advances of
modern time. Einstein recognized that the speed of light in a vacuum is constant, and an absolute
physical boundary for objects in motion. For objects travelling near light speed the theory of relativity
states that: objects will move slower and shorten in length from a point of view on Earth. Einstein
derived the famous equation, E = mc2, which means that Energy is equal to Mass times the speed of
light squared. In simpler terms, it states that there is equivalence between mass and energy.
 Thermal insulator
A method or material used to help prevent or reduce the flow of heat.
 Thermodynamic
Thermodynamics is the study of heat. In science, thermodynamics is the study of energy
conversion between heat and mechanical work.
 Tornado
A destructive windstorm occurring over land, characterized by a funnel-shaped cloud extending
toward the ground.
 Torque
Torque, also called ‘moment’ or ‘moment of force’, is the tendency of a force to rotate an object
about an axis, fulcrum, or pivot. Just as a force is a push or a pull, a torque can be thought of as a
twist.

Totality
The period during a solar eclipse when the Sun is completely blocked by the Moon.
 Transmission
A transmission, also called a ‘gearbox’, is a set of gears that provides speed and torque
conversions from a rotating power source to another device using gear ratios.
 Transpiration
Transpiration is a process similar to evaporation. It is the loss of water from parts of plants,
especially leaves, but also stems, flowers and roots. Leaf surfaces are dotted with openings called
stomata, and in most plants they are more numerous on the undersides of the foliage.
 Triceps
The upper arm muscles used for extending the elbow.
 True North
True north is the direction along the earth’s surface towards the geographic North Pole.
 Turbulent
he unstable flow of a liquid or gas.
 Umbra / Penumbra
The umbra, penumbra and antumbra are the names given to three distinct parts of a shadow,
created by any light source.
The umbra is the area of total darkness in a shadow caused by an eclipse, while the
penumbra is a fringe region of partial shadow around an umbra.
 Venation
The arrangement of veins in a leaf.
 Viscosity
The resistance of a liquid to shear forces and hence its ability to flow. For example: Water or
alcohol has a low viscosity while oil or honey has a high viscosity.
 Vitamin C
Vitamin C, also known as ‘ascorbic acid’, is a water-soluble nutrient essential for life,
synthesized by most animals and plants, but not humans, although used in our bodies for many
purposes. It is plentiful in citreous fruits and many vegetables. A vitamin C deficiency causes a
disease called scurvy.
 Vitamin E
A fat-soluble vitamin that is essential for normal reproduction; an important antioxidant that
neutralizes free radicals in the bodies of plants, animals and humans.
 Volcano
A rupture in the earth’s or another planet’s crust through which molten lava and gases erupt.
 Volt
The volt (symbol: V) is the SI derived unit of electromotive force, commonly called “voltage”. A
unit of potential equal to the potential difference between two points on a conductor, carrying a
current of 1 ampere when the power dissipated between the two points is 1 watt; equivalent to the
potential difference across a resistance of 1 ohm when 1 ampere of current flows through it.
 Von Frey
Max von Frey was a German physiologist, best known for his investigations into the sensations
of pain and touch. Born in 1852, he is known to have established that the skin has separate spots for
cold, warmth, touch and pain. Von Frey used a set of hairs, carefully graded from ‘soft’ to ‘stiff’ in
experiments investigating physical senses which became known as ‘Von Frey’s hairs’ or a ‘Von Frey
device’.
 Vortex
A vortex is the spinning flow of any fluid. The motion of the fluid swirling rapidly around a
centre is called a vortex. A powerful circular current of water is referred to as a whirlpool.
 Water pressure
The force exerted by water that has been compressed.

Water turbine
A water turbine is similar to a waterwheel and is a device that uses falling or flowing water to
create energy. There are a set of paddles or rotors mounted around the wheel. The force of the water
moves the paddles, causing the wheel to turn. The wheel then transmits power to a shaft.
 Water vapour
Water in its gaseous state, produced from liquid water by evaporation. Its presence in the
atmosphere contributes to humidity.
 Watts
The watt is a derived unit of power in the International System of Units (SI), named after the
18th-century Scottish engineer James Watt. One watt is the amount of energy used in one second by
one ampere current under a voltage potential of one volt.
 Weather forecast
A prediction of future weather, often for a specific locality, in a newspaper or on the radio or television.
 White light
Light, having a mixture of frequencies, being perceived as having no specific colour, such as
sunlight or a white-coloured light or lamp.
 Wind vane
A mechanical device attached to an elevated structure. It rotates freely to show the direction of
the wind.
 Windmill
A windmill is a machine which converts the energy of wind to rotational motion by means of
adjustable vanes or blades.
 Work
Work is defined as the result of applying a force to an object in order to move it a certain distance.
 Worker ants
All worker ants are females and live about 1-4 years. They are the smallest, but they do the
most work. They care for the queen and her eggs. Worker ants build and repair the nest, search for
food and fight off enemies.