Radiation and Radioactivity

An alpha particle is also known as

• an electron.

• a helium nucleus.

• a proton.

• a neutron.

The diagram shows a reaction. Which statement BEST describes the type of reaction and the overall energy change that occurs?

• The reaction is fission

• a proton

• a helium nucleus

• a neutron

Radioactive isotopes

• have very unstable nuclei.

• have the most stable nuclei.

Which of the following common household items relies on the properties of the isotope americium-241 to function properly?

• smoke detector

• fire extinguisher

• electric kettle

• alarm clock

What percentage of a radioactive isotope remains after it decays for 2 half-lives?

• 25%

• 50%

• 75%

• 100%

A scientist is studying the emissions produced by a sample of radioactive matter. The scientist observes an emission from the sample pass through a sheet of paper and aluminum. What type of emission did the sample produce?

• gamma ray
• alpha decay

• beta decay

Atomic number and mass number do not change in this type of nuclear decay. What is this decay?

• alpha emission

• beta emission

• gamma emission

• neutron emission

This individual accidentally discovered a process when working with uranium salts on a photographic plate. Who is this scientist?

• Antoine Henri Becquerel

• Marie Curie

• Pierre Curie

• Ernest Rutherford

This type of nuclear decay has the lowest penetrating power. It can only penetrate 0.05 mm into the body and can be stopped by a piece of paper or clothing.

• Alpha

• Beta

• Gamma

• none of these

What happens during radioactive decay?

• Atoms gain electrons

• Atoms lose protons

• Atoms become more stable by emitting particles

• Atoms combine to form new elements