Question 1

The time needed for a radioactive sample to decay to one-half of its original activity is called the ________.

Accepted Answer

The answer of The time needed for a radioactive sample...

Question 2

Exposure to radiation is unavoidable because some radioactive elements occur naturally.

Accepted Answer

This is true. Radiation occurs naturally in the environment from sources such as the sun, cosmic rays, and radioactive materials in the earth's crust.

Question 3

Nuclear fusion does not occur naturally.

Accepted Answer

Nuclear fusion occurs naturally in stars, including the sun, where hydrogen nuclei fuse to form helium, releasing energy.

Question 4

Irradiated food contains small amounts of added radioactive isotopes.

Accepted Answer

Irradiated food does not contain added radioactive isotopes; the process uses ionizing radiation to kill bacteria and pests without making the food itself radioactive.

Question 5

One mCi of a radioactive substance emits more radiation than one μCi of the same substance.

Accepted Answer

"mCi" stands for milliCurie, which is one thousandth of a Curie. Similarly, "μCi" stands for microCurie, which is one millionth of a Curie. Since one mCi is a larger quantity of the same substance compared to one μCi, it will emit more radiation.

Question 6

One type of radiation that is not usually used for medical procedures is the cosmic ray.

Accepted Answer

Cosmic rays are high-energy particles from outer space and are not typically used in medical procedures due to their high energy and potential to cause damage to human tissue.

Question 7

An alpha particle is emitted when Am-241 decays to Np-237.

Accepted Answer

An alpha particle is emitted in the decay of Am-241 to Np-237.

Question 8

Medical radioisotopes used for diagnostic purposes typically have short half-lives.

Accepted Answer

Medical radioisotopes used for diagnostic purposes typically have short half-lives, which allows for less radiation exposure to patients while still providing accurate imaging results.

Question 9

A beta particle is emitted when Co-60 decays to Fe-60.

Accepted Answer

Co-60 decays to Ni-60, not Fe-60, by emitting a beta particle.

Question 10

If the half-life of hydrogen-3 is 11.8 years, after two half-lives the radioactivity of a sample will be reduced to one-half of the original amount.

Accepted Answer

After two half-lives, the radioactivity of a sample will be reduced to one-fourth of the original amount, not one-half.

Question 11

Irradiation of food for sterilization is usually carried out using gamma irradiation.

Accepted Answer

Gamma irradiation is one of the methods used for sterilizing food by killing microorganisms like bacteria, viruses, and parasites. It is widely used in the food industry to extend the shelf life of packaged foods and to ensure the safety of ready-to-eat products. Other methods of food irradiation include electron beam irradiation and X-ray irradiation.

Question 12

The correct symbol for hydrogen-3 is  He.

Accepted Answer

The correct symbol for hydrogen-3 is ³H or tritium, not 11eaafb3_bff4_328e_892c_5bdb9d7d4869_TB6076_11 He, which is not even a valid symbol.

Question 13

The process by which a large nucleus breaks into smaller pieces, releasing large amounts of energy is called nuclear ________.

Accepted Answer

The answer of The process by which a large nucleus...

Question 14

The radioisotope used as a diagnostic tool to measure thyroid function is ________.

Accepted Answer

The answer of The radioisotope used as a diagnostic tool...

Question 15

The diagnostic imaging technique that depends on magnetic fields and radio waves, not radioactivity, is called ________.

Accepted Answer

The answer of The diagnostic imaging technique that depends on...

Question 16

Nuclear fission as used in nuclear power plants produces radioactive waste with long half-lives.

Accepted Answer

This is true, as nuclear fission involves the splitting of atoms which results in the creation of radioactive waste with long half-lives.

Question 17

The common unit of radioactivity which is used to measure the biological damage is the ________.

Accepted Answer

The answer of The common unit of radioactivity which is...

Question 18

The production of nitrogen-13 and a neutron from boron-10 by bombardment with a helium-4 nucleus is an example of radioactive decay.

Accepted Answer

This is not an example of radioactive decay, but rather a nuclear reaction.

Question 19

One symptom of radiation sickness is an increased production of red blood cells.

Accepted Answer

Radiation sickness typically causes a decrease in blood cell production, including red blood cells, due to damage to the bone marrow.

Quiz 5: Nuclear Chemistry