Radioactivity Revision Recall Quiz 2

Which of the following is the correct symbol for a carbon-14 nucleus?

• ⁶₁₄C

• ¹⁴₆C

• ⁸₆C

True or False?

"When a radioactive nucleus emits a beta particle, its atomic number increases."

• True

• False

True or False?

"Radioactive waste from nuclear power stations is often difficult to dispose of safely because it has a long half-life."

• True

• False

In a nuclear reactor, a uranium-235 nucleus can split when...

• it absorbs gamma radiation.

• it collides with an electron.

• it collides with a neutron.

Energy is released in a fusion reaction because ...

• there is a gain in mass by the nuclei involved in the reaction.

• there is a loss of mass from the nuclei involved in the reaction.

• protons are turned into neutrons during the reaction.

Which of the following gives the number of neutrons in the nucleus of an atom?

• The mass number

• The mass number + the atomic number

• The mass number - the atomic number

The count rate of a radioactive sample falls from 130 Bq to 32.5 Bq in 15 minutes.

What is its half-life?

• 15 minutes

• 30 minutes

• 3 minutes 45 seconds

• 7 minutes 30 seconds

Nuclear fission reactions release high-energy neutrons. The role of the moderator in a nuclear reactor is to ...

• limit the rate of fission by absorbing excess neutrons.

• slow the neutrons down so they can be absorbed by uranium nuclei.

• transfer energy from the neutrons to the water in the heat exchanger.

• shield the ionising radiation released during fission.