Radioactivity Part 1 Quiz

Radioactivity is the spontaneous emission of particles or energy from an unstable atomic nucleus to achieve a more stable state.

Henri Becquerel discovered radioactivity accidentally in 1896 while studying phosphorescence of uranium salts.

Alpha particles are identical to the nucleus of a helium atom, consisting of two protons and two neutrons.

Beta particles are high-energy electrons (or positrons) emitted from the nucleus during radioactive decay.

A Geiger-Müller counter (or Geiger counter) is a well-known instrument used for detecting and measuring ionizing radiation.

Background radiation refers to the constant, low level of radiation present in the environment from natural sources (like radon gas from rocks, cosmic rays from space) and some human activities.

Alpha particles are large and relatively slow, easily stopped by a sheet of paper, clothing, or even the outer layer of skin.

Gamma rays, being electromagnetic waves, have no mass or charge and can penetrate most materials deeply, requiring dense shielding like thick lead or concrete.

Gamma rays are massless and chargeless electromagnetic radiation, similar to X-rays but with higher energy, emitted from the nucleus.

Lead is used to block gamma rays because it is very dense and can absorb and stop this powerful form of radiation much better than materials like paper or plastic. Dense materials like lead are most commonly chosen for shielding in hospitals and nuclear facilities to keep people safe from exposure.