S: U6

Endothermic

A chemical reaction that ABSORBS energy

Chemical equations

A short, easy way to show a chemical reaction using symbols

Exothermic

Chemical reaction that RELEASES energy

Law of conservation of energy

Energy cannot be created or destroyed but only changed from one form to another

Mass

Measure of how much matter an object is made of

Fusion

Process in which 2 atomic nuclei combine to form a larger nucleus; produces heavier elements and releases a huge amount of energy; produces energy in stars

Law of conservation of matter (mass)

Regardless of how substances (in a closed system) are changed, the total mass remains the same

Products

Substance formed by a chemical reaction; product is made of the rearrangement of atoms and bonds in reactants

Reactants

Substance that is present at the beginning of a chemical reaction & is changed into a new substance

Fission

The process of splitting the nucleus of a radioactive atom; produces lighter elements & releases a huge amount of energy