Question

There are four principal modes of radioactive decay. For each write a balanced chemical equation. Describe the factors that must be present for that mode to occur, and describe how the mode changes the N/Z ratio and leads to a ratio that is closer to or in the zone of stability. please help with all parts of this question im confused, thank you!

Answer 1

Four principal modes of radioactive decay are:

1. Alpha Decay:  In alpha decay, the nucleus emits an alpha particle, or a particle containing two protons and two neutrons.

²³⁸U₉₂ $\rightarrow$    ²³⁴Th₉₀   +   ⁴He₂ ( $\alpha$ particle )

Alpha decay occurs because the nucleus of a radioisotope has too many protons. A nucleus with too many protons causes repulsion between these like charges. To reduce this repulsion, the nucleus emits an $\alpha$ particle.

In an alpha decay N is decreased by 2 and Z is decreased by 2.

2. Beta Decay: The process in which an electron is ejected or emitted from the nucleus is called beta decay.

⁴⁰K₁₉      $\rightarrow$    ⁴⁰Ca₂₀   + ⁰e_-1 (beta particle)

Beta decay occurs when radioactive nuclei have too many neutrons.

During beta decay, the number of neutrons(N) in the atom decreases by one, and the number of protons(Z) increases by one.

3. Gamma Decay: In gamma decay, some unstable atomic nuclei dissipate excess energy by a spontaneous electromagnetic process.

⁶⁰Co₂₇      $\rightarrow$      ⁶⁰Co₂₇ + $\gamma$

Gamma decay reactions occur if the energy of the radioisotope's nucleus is too high.

During gamma decay, the number of neutrons(N) in the atom and the number of protons(Z) remains same.

4. Spontaneous fission: Spontaneous fission is a type of radioactive decay in which certain unstable nuclei of heavier elements split into two nearly equal fragments (nuclei of lighter elements) and liberate a large amount of energy.

²⁵²Cf₉₈ $\rightarrow$    ¹⁴⁰Xe₅₄   +   ¹⁰⁸Ru₄₄   + 4 ¹n₀