Radiation and Radioactivity Quiz

Which type of radiation is stopped by a few cm of lead?

• Alpha

• Beta

• Gamma

• Neutron

Answer explanation

Gamma radiation is highly penetrating and requires dense materials like lead for shielding. A few centimeters of lead can effectively stop gamma rays, while alpha and beta particles are stopped by much less dense materials.

What is emitted during beta-minus decay?

• Proton

• Neutron

• Electron

• Positron

Answer explanation

During beta-minus decay, a neutron in the nucleus transforms into a proton and emits an electron (beta particle) and an antineutrino. Therefore, the correct answer is 'Electron'.

Which of the following is the most ionising?

• Alpha particles

• Beta particles

• Gamma rays

• X-rays

Answer explanation

Alpha particles are the most ionising due to their large mass and charge, which allows them to interact strongly with matter, causing significant ionisation. In contrast, beta particles, gamma rays, and X-rays are less ionising.

Which radiation travels the longest distance in air?

• Alpha

• Beta

• Gamma

• Neutron

Answer explanation

Gamma radiation travels the longest distance in air due to its high energy and lack of mass, allowing it to penetrate materials more effectively than alpha and beta particles, which are more easily absorbed.

The spontaneous nature of radioactive decay means:

• It is caused by temperature

• It cannot be predicted exactly

• It can be stopped by a magnet

• It only occurs in unstable atoms

Answer explanation

The spontaneous nature of radioactive decay means it occurs randomly and cannot be predicted exactly. While it only occurs in unstable atoms, the key point is the unpredictability of when a specific atom will decay.

What happens to atomic number during alpha decay?

• Increases by 2

• Decreases by 2

• Stays the same

• Increases by 4

Answer explanation

During alpha decay, an atomic nucleus emits an alpha particle, which consists of 2 protons and 2 neutrons. This results in a decrease of 2 in the atomic number, as the nucleus loses 2 protons.

Which material is best for shielding gamma radiation?

• Paper

• Aluminium

• Wood

• Lead

Answer explanation

Lead is the most effective material for shielding gamma radiation due to its high density and atomic number, which absorb and scatter gamma rays better than paper, aluminium, or wood.

What changes in the nucleus during beta decay?

• A neutron becomes a proton

• A proton becomes a neutron

• A proton becomes an electron

• A neutron becomes an alpha particle

Answer explanation

During beta decay, a neutron in the nucleus transforms into a proton, emitting an electron and an antineutrino. This process increases the atomic number by one, changing the element.

Which radiation has no mass and no charge?

• Alpha

• Beta

• Gamma

• Neutron

Answer explanation

Gamma radiation has no mass and no charge, making it distinct from alpha particles (which are heavy and positively charged), beta particles (which are electrons or positrons), and neutrons (which have mass but no charge).

What is a common use of gamma radiation?

• Detecting leaks

• Smoke alarms

• Dating rocks

• Power generation

Answer explanation

Gamma radiation is commonly used for detecting leaks in pipelines and containers due to its ability to penetrate materials and identify inconsistencies, making it effective for safety and maintenance checks.