Nuclear Chemistry

Larger Nucleii are Unstable, these achieve stability by losing energy or particles and become lighter and more stable.

This process is called Radioactive Decay.​

Radioactive Decays are represented by Nuclear Reactions.

To Balance Nuclear reactions, you have to balance

Mass Number

Atomic Number​

​

Radioactive decays are defined based on particles emitted. e.g.

• Alpha: He⁴₂ nucleus

• Beta: Electron ⁰_-1e​

• Gamma: No p​articles are emitted. High energy radiation.

• Positron: ​⁰₁e

• Electron Capture: Capture of electron.​

​

Alpha Particle (α​) is emitted.

e.g

​

²³⁸₉₂U​ He⁴₂ + ^238-4=234_92-2=90

​

Look up element with atomic number of 90, it is Th, so product is

²³⁴₉₀Th ​

Alpha Particle (β​) is emitted.

e.g

​

²³⁸₉₂U​ e⁰_-1 + ^238-0=238_92--1=93

​

Look up element with atomic number of 93, it is Np, so product is

²³⁸₉₃Np ​

Gamma Rays (γ​) are emitted. These have no particles

e.g

​

²³⁸₉₂U​ γ + ^238-0=238_92-0=92

​

So there is no change in the nucleus

²³⁸₉₂U ​

Alpha Particle (β​) is emitted.

e.g

​

²³⁸₉₂U​ e⁰_-1 + ^238-0=238_92--1=93

​

Look up element with atomic number of 93, it is Np, so product is

²³⁸₉₃Np ​

Gamma Rays (γ​) are emitted. These have no particles

e.g

​

²³⁸₉₂U​ γ + ^238-0=238_92-0=92

​

So there is no change in the nucleus

²³⁸₉₂U ​