Mrs. Hobbs
TEKS: 2DE, 4ABC, 11ABC
UNIT 2 NOTES: MATTER
Matter – anything that has mass and volume
Mass – the amount of matter in an object; grams
Weight- a measure of the force of gravity on an object; newtons
Astronauts in space are weightless but not massless.
Volume – the space occupied by matter
If an object is less dense than a given liquid, it will float in it.
If an object is more dense than a given liquid, it will sink.
If the density of the object is about the same as the liquid, the object will remain suspended.
Substance – matter that has a uniform and definite composition;
ex.(example) sugar
Intensive and Extensive Properties
o
Intensive - Properties that do not depend on the amount of the matter present.
 Color
 Odor
 Luster - How shiny a substance is.
 Malleability - The ability of a substance to be beaten into thin sheets (ex. metals &
modeling clay)
 Ductility - The ability of a substance to be drawn into thin wires. (ex. metals)
 Conductivity - The ability of a substance to allow the flow of energy or electricity.
 Hardness - How easily a substance can be scratched.
 Melting/Freezing Point - The temperature at which the solid and liquid phases of a
substance are in equilibrium at atmospheric pressure.
 Boiling Point - The temperature at which the vapor pressure of a liquid is equal to
the pressure on the liquid (generally atmospheric pressure).
 Density - The mass of a substance divided by its volume
o
Extensive - Properties that do depend on the amount of matter present.
 Mass - A measurement of the amount of matter in a object (grams).
 Weight - A measurement of the gravitational force of attraction of the earth
acting on an object.
 Volume - A measurement of the amount of space a substance occupies.
 Length
Extensive properties – depend on the amount of substance present;
ex. mass, volume, length
Intensive properties – do not depend on the amount of substance present;
ex. density, color, melting point etc.
4 States of Matter:
1.
Solid – matter with a definite shape and a definite volume;
ex. wood, brick, desk, rock
2.
Liquid – matter with a definite volume but no definite shape;
takes the shape of its container, flows, almost
incompressible;
ex. water, milk, mercury
3.
Gas – matter with no definite volume and no definite shape; takes
the shape and volume of its container, easily compressed; ex. helium, air, oxygen, nitrogen
4. Plasma – matter that has lost its electrons due to
extremely high temperatures (greater than
10,000 oC);
ex. lightning, stars, neon signs, mercury and sodium
vapor street lights
Not a state of matter
solid at room temperature;
ex. gasoline, ammonia
Vapor – the gaseous state of a substance that is generally a liquid or
Phase Change or Change of State: a change from one state (solid, liquid or gas) to another without a
change in chemical composition
Changes of State:
1.
2.
3.
4.
5.
6.
melting – solid to liquid; ex. ice cube at room temp.
freezing – liquid to solid; ex. making ice cubes
evaporation – liquid to gas; ex. puddle drying up, boiling water
condensation – gas to liquid; ex. sweating glass, dew, rain, fogged up mirror
sublimation – solid to gas; ex. dry ice, iodine
sublimation – gas to solid; ex. hailstones, snow
Solids:
1.
2.
3.
4.
5.
Liquids:
1.
2.
3.
4.
5.
Gases:
1.
2.
3.
4.
5.
definite shape & volume
Very dense, particles highly packed
Particles organized in fixed positions
Particles held by strong attractive forces
Not compressible
No definite shape but definite volume
Relatively dense
Particles held by weak attractive forces
Can flow
Not compressible
No definite shape & No definite volume
No attractive forces between particles
Lots of empty space between particles
Can be Compressed
Not very dense
Kinetic Theory – as the temperature of particles increases, the motion of particles increases and
vice versa
Effect of air pressure on boiling point (p. 278):
An increase in air pressure increases the boiling point
A decrease in air pressure decreases the boiling point
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Properties of Matter:
Physical property – a quality or condition of a substance that can
be observed without changing the substance’s
composition
ex. color, odor, hardness, density, luster, solubility, conductivity
malleability, ductility, texture, melting point,
boiling point, etc.
Solubility – the amount of a substance that can dissolve in another substance
Viscosity(noun) or Viscous(adjective) – resistance to flow
ex. honey, syrup
Malleability(noun) or Malleable(adjective) – can be hammered into thin sheets without breaking
ex. metals, modeling clay
Ductility(noun) or Ductile(adjective) – can be drawn into wires
ex. Metals
Conductivity – the ability of a substance to conduct electricity
Physical Change – a change in a substance that does not change its
composition
ex. cutting, grinding, bending, breaking, freezing,
melting, stirring, etc.
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Chemical Property – the ability of a substance to undergo a
chemical reaction and form a new substance
ex. flammability, reactivity, pH, conductivity, etc.
Reactivity – the ability of a substance to combine chemically with
another substance
Flammability – ability of a substance to burn
pH – a measure of the strength of acids and bases
Chemical Change – a change in a substance that does change its
composition
ex. burning, combustion, rusting, rotting, decaying,
decomposing, digesting, fermenting, growing, oxidation,
tarnishing
Tarnishing – when silver turns dark due to reaction with oxygen
Oxidation – reaction of a substance with oxygen, like rusting or
tarnishing of metals
Indicators of a chemical reaction:
1. energy absorbed or given off (usually heat)
2. color change
3. odor given off
4. production of a gas
5. production of a solid
6. bubbling
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Mixtures & Compounds
Mixture – a combination of substances not chemically combined; ex. stew, salad, saltwater, milk, sulfur
and iron filings, staples and paper clips etc.
Compound – a chemical combination of atoms of two or more elements; abbrv. Cpd. Ex. H2O, CO2, C6H12O6
Homogeneous mixture – completely uniform in composition;
ex. solutions, homogenized milk
Solutions – homogeneous mixture of two or more substances; may be any combination of gases, liquids, or
solids, any sample of a solution has the same composition of any other portion of the solution, abbrev.
soln.
ex. air is a mixture of gases, saline soln., glucose (IV) soln.
Alloy – a physical mixture (solid solution) made by melting together 2 or more elements, at least one of
which is a metal
ex, brass, bronze, stainless steel, sterling silver
Heterogeneous mixture – not uniform in composition;
ex. soil, real milk, stew, salad
**Components of a mixture can be separated by physical means such as filtration, magnetism, distillation
Filtration – like a coffee filter separating coffee grounds from liquid coffee, filter solids out of a liquid
Distillation – boiling something like salt water until all the water is evaporated leaving the salt behind
Chromatography – a physical method of separating the components of a mixture where one phase is
stationary and the other phase moves
Magnetism – iron, nickel and cobalt can be separated from other materials by attracting them to another
magnet
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Levels of Matter:
Atom – the smallest particle of an element that still retains the properties of that element
Element – a pure substance made up of atoms that cannot be changed into a simpler substance under normal laboratory
conditions
Elements can be broken into simpler particles (p+’s, no’s, e-‘s) by nuclear reactions. However, they lose their
characteristic properties when this happens. Also, large amounts of energy are released.
Compound – a chemical combination of atoms of two or more elements; abbrv. Cpd. Ex. H 2O, CO2, C6H12O6
Chemical Reactions- when one or more substances are changed into a new substance, requires energy; these involve primarily
electrons and the making and breaking of chemical bonds
Reactants – starting substances
Products – new substances formed
Chemical Symbol - a one or two-letter symbol that represents an element, the first letter is always capitalized and the second
is always lower case, the newest man-made elements may have a 3-letter symbol; C-carbon, Fe-iron
HIERARCHY OF MATTER
Hierarchy – a governing body whose members are arranged in ordered ranks; arrangement into a graded series of
classes or ranks
p+, no, e-
(simplest forms of matter)
atoms
elements
compounds
non-living matter (most complex forms of matter) living matter
(rocks, air, water)
(humans, plants, animals)
cells
tissues
organs
organ systems
organisms (you, dog, tree)
LAW OF CONSERVATION OF ENERGY – IN ANY CHEMICAL OR PHYSICAL PROCESS, ENERGY IS NEITHER CREATED
NOR DESTROYED
**Energy is transformed from one form to another, however, it is never destroyed**
Ex. Radiant Energy (light & heat) from the sun is converted into chemical energy by plants through the process of
photosynthesis. Animals then eat the plants and convert the chemical energy into energy for life processes and in turn lose
heat energy back to the atmosphere, but the energy is never destroyed. In the atmosphere, the heat energy contributes to the
hydrologic cycle.
LAW OF CONSERVATION OF MASS – IN ANY CHEMICAL OR PHYSICAL PROCESS, MASS IS NEITHER CREATED OR
DESTROYED, IT IS CONSERVED
This law is why all chemical reactions must be balanced. Atoms are never destroyed, they are just rearranged in ordinary
chemical reactions.
The total mass of the reactants (starting substances) must equal the total mass of the products (new substances formed).
This law implies that all atoms present at the beginning of time are still present in some form today. They are just constantly
recycled.