Unit 4 Chemical Changes

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Combustion
A chemical change that releases thermal energy and light; the process of burning something
Equilibrium
A state of balance
Subscript
A number in a chemical formula that tells the number of atoms in a molecule or the ratio of elements in a compound; the small number to the right of an element
Compound
A substance made up of atoms of two or more different elements joined by chemical bonds
Law of Conservation of Mass
Matter is not created nor destroyed in any chemical or physical change
Molecule
Two or more atoms bonded together;
smallest unit of most compounds
Chemical Formula
A combination of symbols that represents the elements in a compound.
Mass
A measure of the amount of matter in an object
Yields
Makes, creates, produces; the arrow in chemical equation
Chemical Reaction
Process that changes, or transforms, one set of chemicals into another set of chemicals
Product
A chemical substance formed as a result of a chemical reaction; found on the right side of the arrow
Coefficient
A number in front of a chemical formula in an equation that indicates how many molecules or atoms of each reactant and product are involved in a reaction; the big number in front
Reactant
A chemical substance that is present at the start of a chemical reaction; found on the left side of the arrow
Atom
The basic unit of matter
Chemical Change
A change in matter in which the matter becomes a new kind of matter with new properties
Element
A pure substance made of only one kind of atom
Matter
Anything that has mass and takes up space
Physical Change
A change in which no new substances are formed
Precipitate
A solid that forms and settles out of a liquid mixture
Property
A characteristic or description of a substance
Synthesis
Combining of small molecules or substances into larger, more complex ones