Radioactivity and types of radiation

Introduction to radioactivity

Everything you see is made of tiny atoms. Usually, these atoms are stable and happy. But some atoms have a very heavy center, called a nucleus, that is vibrating and shaking because it has too much energy. This makes the atom unstable.

Imagine a kerosene stove that is leaking. To stop the pressure, it must release some gas. In the same way, an unstable nucleus will spit out tiny particles or energy to become stable. This process of spitting out particles is what we call radioactivity.

Simply put, radioactivity is an atom breaking down on its own to reach a peaceful state.

Characteristics of radioactivity

Radioactivity is spontaneous. This means it happens on its own without anyone pushing it. It does not care if the weather is hot or cold, or if the pressure is high. It is different from ordinary chemical reactions where you might need to heat your pot of soup to make it cook faster.

Three types of radiation

When an atom breaks down, it sends out three main types of 'bullets' or rays. Scientists discovered these by passing them through an electric field, just like how NEPA wires have positive and negative sides.

Alpha particles (symbol: alpha)

These are the heavyweights. They are actually Helium nuclei, written as He₂⁴. Because they are heavy, they move slowly. They have a positive charge, so they are attracted to the negative plate in an electric field.

Alpha particles have very low penetrating power. Even a thin sheet of paper or your school uniform can stop them from passing through.

Beta particles (symbol: beta)

These are fast-moving electrons, written as e_-1⁰. They are much lighter than alpha particles and carry a negative charge. Because they are negative, they curve toward the positive plate in an electric field.

Beta particles have more 'spirit' than alpha; they can pass through paper but are stopped by a thin sheet of aluminum metal.

Gamma rays (symbol: gamma)

Gamma rays are not particles at all; they are pure energy, like very strong light or X-rays. They have no charge and no mass. Because they have no charge, they go straight through an electric field without turning left or right.

Gamma rays are the most dangerous and powerful. They can pass through paper and aluminum. You need a thick block of lead or concrete, like the walls of a strong room, to stop them.

Summary of properties:

Alpha: Positive charge (+2), mass of 4, lowest penetration, highest ionizing power.

Beta: Negative charge (-1), mass of 0, medium penetration, medium ionizing power.

Gamma: Neutral charge (0), mass of 0, highest penetration, lowest ionizing power.