Nuclear Chemistry Quiz/Test Study Guide/Review

by: Kareem

Henri Becquerel

Discovered radioactivity in 1896 while studying uranium

Marie and Pierre Curie

Discovered polonium and radium; coined the term "radioactivity"

Alpha Decay

Releases 2 protons and 2 neutrons; atomic number decreases by 2 and mass by 4

Beta Decay

A neutron turns into a proton and emits an electron; atomic number increases by 1

Gamma Radiation

High-energy waves emitted with no change in mass or charge

Chemical Reaction

Involves electron rearrangement; small energy change

Nuclear Reaction

Involves nucleus changes; very large energy release

Fission

Heavy nucleus splits into smaller ones; used in nuclear reactors and bombs

Fusion

Light nuclei combine into a heavier one; powers the Sun and hydrogen bombs

Nuclear Equation Balancing

Mass and atomic numbers must be equal on both sides of the equation

Half-Life

Time for half of a radioactive sample to decay

Half-Life Formula

N = N₀ × (½)^(t / t₁/₂)

Alpha Shielding

Stopped by paper or skin

Beta Shielding

Stopped by aluminum foil

Gamma Shielding

Stopped by lead or thick concrete

Example of Alpha Decay

²³⁸₉₂U → ²³⁴₉₀Th + ⁴₂He

Example of Beta Decay

¹⁴₆C → ¹⁴₇N + ⁰₋₁e

Example of Fission

²³⁵U + n → ¹⁴¹Ba + ⁹²Kr + 3n

Example of Fusion

²H + ³H → ⁴He + n

Half-Life Example

A 100 g sample with a 10-year half-life will have 12.5 g left after 30 years