Unit 3 Chemistry

Alpha Decay

Emits an alpha particle (2 protons and 2 neutrons); decreases atomic number by 2 and mass number by 4.

Beta Decay

Emits a beta particle (an electron or positron); a neutron changes into a proton or vice versa; increases or decreases atomic number by 1.

Gamma Decay

Emits a gamma ray (high-energy electromagnetic wave); no change in atomic number or mass number.

Belt of Stability

Shows stable isotopes based on the neutron-to-proton ratio (N/Z ratio).

Half-Life

The time it takes for half of a radioactive substance to decay.

Nuclear Fission

The splitting of a heavy nucleus into smaller nuclei, releasing a large amount of energy.

Nuclear Fusion

Combining of two light nuclei to form a heavier nucleus, releasing more energy than fission.

Half-Life Calculation Example

If a sample has a half-life of 10 years, starting with 80g, 10g remains after 30 years.