Unit 4 Vocab Chemistry
Matter – anything that has mass and takes up space
Meniscus – the curve at the surface of a liquid
Inertia – tendency of an object to resist a change in motion
Physical property – can be observed or measured w/o changing the identity
Thermal conductivity - rate at which a substance transfers heat
Solubility – ability of a substance to dissolve in another substance
Ductility – ability of a substance to be pulled into a wire
Malleability – ability of a substance to be rolled or pounded into thin sheets
States of matter – solid, liquid, gas
Specific heat – amount of energy needed to change the temperature of 1 Kg by 1˚ C
Physical change – a change that affects one or more physical properties of a
Substance
Chemical property – describe matter based on its ability to change into new matter
With new properties
Flammability – ability of a substance to burn
Reactivity – ability of 2 or more substances to combine and form new substances
Characteristic properties – properties most useful in identifying a substance
Chemical change – when one or more substances changed into a new one with new
Properties
Precipitate – when 2 substances that are dissolved in water combine to form a
cloudy solid
composition – the type of matter that makes up the object and how its arranged
electrolysis – water broken down into hydrogen and oxygen gases
atoms – smallest unit of an element that has all the properties of that element
molecules – smallest unit of a compound that has all the properties of it
solid – state of matter that has definite shape and volume
crystalline – very orderly, 3 dimensional arrangement of particles ( diamond, ice)
amorphous – particles not in any special order ( glass, rubber)
liquid – state of matter with definite volume, takes the shape of the container
surface tension - a force that acts on the particles at the surface of liquid
viscosity – a liquids resistance to flow
gas – state of matter that has no definite shape or volume
thermal expansion – increase in volume of a substance due to increase in
temperature
absolute zero – temperature at which all molecular motion stops
melting – change of state from a solid to a liquid
endothermic – energy is gained by the substance as it changes state
freezing – change of state from a liquid to a solid
exothermic – energy is removed from the substance as it changes
evaporation – change of state from a liquid to a gas
boiling – change of a liquid to a vapor, pressure inside bubble equals outside pressure
vapor pressure – pressure inside boiling bubbles
condensation – change of state from a gas to a liquid
sublimation – change of state when solid goes directly to a gas. ( dry ice)
element – pure substance that cannot be separated into simpler substances
pure substance = substance with only one type particle
metals – shiny, conduct heat energy and electric current, malleable
non-metals – dull, do not conduct heat or electric, brittle
metalloids – properties of both metals and nonmetals, called semiconductors
compounds – pure substance composed of 2 or more elements chemically combined
specific ratio – elements, combine according to their mass
cohesion – force that holds molecules of a single material together ( water drop)
adhesion – attractive force between 2 different substances in contact (wet clothes)
universal solvent – water because most all substances dissolves in it, its polarity
polar – water because it has 2 areas that have opposite charges. Positive hydrogen
and negative oxygen
solvent – substance in which other substances dissolve ( water in salt water)
solute- substance that is dissolved ( salt in salt water)
buoyant force – upward force that fluids exert on all mater
mixture – combination of 2 or more substances that are not chemically combined
solution – mixture that appears to be a single substance
insoluble – unable to dissolve
suspension – mixture in which particles of a material are dispersed throughout a
liquid or a gas but are large enough they settle out
colloid – mixture in which the particles are dispersed throughout but are not heavy
enough to settle out
concentration – measure of the amount of solute dissolved in a solvent
Mendeleev – Father of he periodic table. Discovered pattern of periodic table
Periodic – happens at regular intervals
Periodic law – repeating chemical and physical properties of elements change with
the atomic number
semiconductors – mettaloids
period – horizontal row of elements ( left to right)
group – vertical column of elements ( top to bottom)
transition – all metals , middle section
lanthanides – shiny reactive metals, 1st bottom row
actinides – all radioactive or unstable, 2nd bottom row
halogens – very reactive nonmetals
nobel gases – unreactive non metals, last group on periodic table
chemical bonding – joining of atoms to form new substances
atomic number – number of protons
valence electrons – electrons in the outermost energy level of an atom
ionic bonds – bond that forms when electrons are transferred from one atom to another
ions – charged particles that form when atoms gain or loose electrons
crystal lattice – a repeating 3 dimensional pattern when ions bond
covalent bond – when atoms share one or more pairs of electrons
diatomic molecule – molecule made up of 2 atoms of the same element
metallic bond – a bond formed by the attraction between positively charged metal
ions and the electrons in the meta
chemical reaction – process in which one or more substances change to make a new
one with its own properties
chemical formula – shorthand way to use chemical symbols and numbers to
represent a substance
chemical equation – chemical symbols and formula to describe a chemical reaction
reactants – starting materials in a chemical reaction
product – substance formed when the reactants chemically react
closed system – a system where total mass does not change
Law of conservation of mass – mass is neither created nor destroyed in ordinary
chemical and physical changes
coefficient – number that is placed in front of chemical symbol
subscript – the number of the specific type of atom in the formula
synthesis reaction – 2 or more substances combine to form 1 new compound
A+B yields AB
Decomposition reaction – reaction in which a single compound breaks down to form
2 or more simpler elements AB yields A + B
single displacement reaction – an element replaces another element in a compound
AB + C yields A + BC
Double displacement reaction – ions form 2 compounds and then change places
AB + CD yields AC + BD
Law of conservation of energy – energy cannot be created or destroyed, but can
change form
activation energy – smallest amount of energy that molecules need to react
inhibitor – a substance that slows down or stops a chemical reaction
catalyst – a substance that speeds up a reaction without being permanently changed
(enzymes in your body)
chemical – any substance with a defined composition
natural chemical – chemical found in nature
synthetic chemical – something made by humans – not natural
medicine – a substance that is used to cure, prevent or treat illness
potency – the power of a medicine to produce its desired effect
dose – amount of medicine that needs to be taken @ one time
food preservative – chemical that can prevent or slow down the spoiling of food
fertilizer – a chemical that improves the quality of the soil to produce plants
pesticide – a poison that is used to kill insects, weeds and other crop pesticides
sodium hypochlorite – bleach
exposure – being in contact with a chemical
individual susceptibility – a person’s rick of being affected negatively by something
dangerous
carcinogen – cancer causing
autoimmune disease – a disease in which a persons immune system attacks certain
cells, tissue or organs
FAS – fetal alcohol syndrone
Diabetes- disease affects the body’s ability to use or make sugar
Lead poisoning – results in learning and behavioral disorders
Cancer – disease caused by uncontrolled cell growth