Quiz on Radioactivity and Radiation

Which of the following is not a type of radiation emitted during radioactive decay?

• Alpha particles

• Beta particles

• Gamma rays

• X-rays

Answer explanation

X-rays are not emitted during radioactive decay; they are a form of electromagnetic radiation produced by electronic transitions. In contrast, alpha particles, beta particles, and gamma rays are all types of radiation released during radioactive decay.

Alpha particles consist of:

• 2 protons and 2 neutrons

• 2 protons and 2 electrons

• 1 proton and 2 neutrons

• 1 proton and 2 electrons

Answer explanation

Alpha particles are made up of 2 protons and 2 neutrons, which is the same as a helium nucleus. This composition distinguishes them from other particles, making the correct answer 2 protons and 2 neutrons.

Which particle has the greatest penetrating power?

• Alpha particle

• Beta particle

• Gamma ray

• Neutron

Answer explanation

Gamma rays have the greatest penetrating power due to their high energy and lack of mass or charge, allowing them to pass through materials more easily than alpha particles, beta particles, or neutrons.

Beta particles are:

• Positively charged

• Negatively charged

• Neutral

• Photons

Answer explanation

Beta particles are negatively charged electrons or positrons. In the context of beta decay, they are specifically electrons, which carry a negative charge, making 'Negatively charged' the correct answer.

The half-life of a radioactive element is the time taken for:

• Half of the atoms to decay

• Half of the mass to disappear

• Half of the volume to change

• The entire sample to disintegrate

Answer explanation

The half-life of a radioactive element refers to the time required for half of the atoms in a sample to decay. This means that after one half-life, 50% of the original atoms remain, confirming the correct choice.

Gamma rays are:

• Electrons

• Electromagnetic waves

• Neutrons

• Protons

Answer explanation

Gamma rays are a form of electromagnetic radiation, characterized by high energy and short wavelengths. They are not particles like electrons, neutrons, or protons, making 'Electromagnetic waves' the correct choice.

Which radiation can be stopped by a sheet of paper?

• Alpha particles

• Beta particles

• Gamma rays

• X-rays

Answer explanation

Alpha particles are the least penetrating type of radiation and can be stopped by a sheet of paper. In contrast, beta particles, gamma rays, and X-rays require denser materials for shielding.

Which of the following is a characteristic of radioactive substances?

• Stability over time

• Spontaneous emission of radiation

• Decreasing mass with time

• Increase in temperature

Answer explanation

Radioactive substances are characterized by the spontaneous emission of radiation as they decay. This process occurs without external influence, distinguishing them from stable materials.

A Geiger-Muller counter is used to measure:

• Heat

• Electric current

• Radioactivity

• Speed

Answer explanation

A Geiger-Muller counter is specifically designed to measure radioactivity by detecting ionizing radiation. It cannot measure heat, electric current, or speed, making 'Radioactivity' the correct choice.

The unit of radioactivity is:

• Becquerel (Bq)

• Coulomb (C)

• Tesla (T)

• Watt (W)

Answer explanation

The unit of radioactivity is the Becquerel (Bq), which measures the rate of decay of radioactive material. The other options (Coulomb, Tesla, Watt) are units for electric charge, magnetic flux density, and power, respectively.