Chem Ch.19

Question 1

List some uses of radioactive elements and discuss why knowing their half-lives is
important

Answer 1

Carbon-14 is used to work out the age of fossils or wooden objects. Living things absorb carbon dioxide and other carbon compounds. Some of the carbon atoms are carbon-14, which is a radioactive isotope of carbon. Carbon-14 has a half-life of about 5,700 years. Half-life’s are important to predict the concentration of a substance over time.

Question 1

Describe how to perform half-life calculations

Answer 1

1.Determine the original amount of the 2.substance.
3.Determine the amount of time for which the substance was measured.
4.Determine the remaining amount of the substance after the time.
5.Substitute these values into the half-life equation and solve for half-life.

Question 2

Give a general overview of how a Geiger counter works

Answer 2

A Geiger counter has two main parts—a sealed tube, or chamber, filled with gas, and an information display. Radiation enters the tube and when it collides with the gas, it pushes an electron away from the gas atom and creates an ion pair.

Question 3

Describe how transuranium elements are made through the process of nuclear transformation

Answer 3

An important method of synthesizing transuranium isotopes is by bombarding heavy element targets not with neutrons but with light charged particles (such as the helium nuclei mentioned above as alpha particles) from accelerators.

Question 4

Describe the difference between nuclear fusion and nuclear fission

Answer 4

Fission is the splitting of a heavy, unstable nucleus into two lighter nuclei, and fusion is the process where two light nuclei combine together releasing vast amounts of energy.

Question 5

Describe the way in which a nuclear fission reactor produces energy

Answer 5

Nuclear power reactors use heat produced during atomic fission to boil water and produce pressurized steam. The steam is routed through the reactor steam system to spin large turbines blades that drive magnetic generators to produce electricity.

Question 6

Describe the penetrating ability of alpha, beta, and gamma radiation

Answer 6

Beta particles can partially penetrate skin, causing “beta burns”. Alpha particles cannot penetrate intact skin. Gamma and x-rays can pass through a person damaging cells in their path. Neutron radiation present during nuclear reactions, within a few miles of ground zero, is as penetrating as gamma rays.

Question 6

List what factors determine the effects of radiation on biological organisms

Answer 6

The effects of radiation depend on the type, energy, and location of the radiation source, and the length of exposure.