Chapter 11: Nuclear Chemistry

CFE, Sp26

Background radiation

where ¾ of all exposure to radiation comes from

Medical irradiation, x-rays

¼ of radiation

Ionizing radiation

removing electrons from molecules to form ions in cells, disrupts DNA causing mutations

Free radicals

disrupt cellular processes

Radiation

affects the fastest-growing cells and tissues, white blood cells and bone marrow

Nucleons

protons and neutrons

atomic number

number of protons

mass number

number of nucleons

Alpha

very low penetrating power

Beta

moderate penetrating power

Gamma

Extremely high penetrating power

Positron emission

particle equal in mass to an electron with with opposite charge

Electron capture

nucleus absorbs an election from the inner shellwZx

half-life of a radioactive sample

time required for one-half of the material to undergo radioactive delay

Tracers

Radioisotopes can be easily detected through their decay products

Tracers include

leaks in underground pipes, uptake phosphorus and its distribution in plants

Nuclear Medicine

Radiation therapy

Radiation therapy

nuclear radiation can be used to kill cancerous cells

Radiation

most lethal to fastest-growing cells

Alpha Radiation

least penetrating and can’t penetrate the outer layer of skin, stopped by a sheet of paper

Beta radiation

penetrate through few centimeters of skin and tissue, stopped by sheet of aluminum foil

Gamma radiation

pass right through a body, several centimes of lead to stop

Nuclear fission

fission occurs when larger nuclei split into smaller nuclei

Chain reaction

concentration dependent the concentration needed to sustain a chain reaction; critical mass

Nuclear chain reaction

controlled for the slow release of heat energy. heat used to make steam which turns a turbine to produce electricity

Critical mass

sustain the nuclear fission reaction

radioactive isotope

produced in a nuclear bomb blas

nuclear fusion

thermonuclear reaction in which smaller atomic necks are fused into larger nuclei

fusion

principal reaction in the sun

When radon-222 undergoes alpha decay, what other product is formed?

polonium-218

Phosphorus-30 decays by positron emission. The product is

silicon-30

After one half-life, 50% of a radioactive sample will remain. After the second half-life, none of the radioactivity will be left.

False

Nitrogen-13 has a half-life of 10 minutes. How much of a 64 mg sample would remain after 40 minutes?

4 mg

Positron emission tomography (PET) is a

diagnostic technique for monitoring dynamic processes in the body, such as brain activity

Which one of the following is most penetrating?

gamma ray

The source of the energy produced by the sun is

the fusion of primarily hydrogen

Critical mass is

the minimum amount of fissionable material that will sustain a chain reaction