| A | B |
|---|
| activation energy | the least amount of energy required to start a particular chemical reaction |
| catalyst | a substance that speeds up or slows down the rate of a reaction without being consumed or altered |
| covalent bond | a chemical bond between two atoms of the same or different elements in which each atom shares an electron |
| half-life | the amount of time required for half of an original sample of radioactive material to decay or undergo radioactive transformation |
| mass number | the total number of protons and neutrons in a nucleus |
| nuclear fission | the process by which an atomic nucleus splits into two or more large fragments of comparable mass, simultaneously producing additional neutrons and vast amounts of energy |
| nuclear fusion | the process by which two lighter atomic nuclei combine at extremely high temperatures to form a heavier nucleus and release vast amounts of energy |
| product | a substance or compound resulting from a chemical reaction |
| rate of reaction | the speed at which reactants are consumed and products are produced in a given reaction |
| reactant | any substance or molecule that participates in a chemical reaction |
