Mastering Chemistry Chapter 11

more , alpha, humans

A naturally occurring transmutation occurs when an element decays on its own to become a ________ stable element. One example is the __________ and beta decay series of uranium. An artificial transmutation occurs when a nuclear reaction is induced by __________.

5730 yr

A piece of wood from an Egyptian tomb has a carbon-14 activity of 2410 counts/h . A piece of new wood of the same size shows 4820 counts/h . What is the age of the wood from the tomb? The half-life of carbon-14 is 5730 years.

increasing the number of red blood cells

All of the following can be a consequence of ionizing radiation except: sickness decreasing the number of white blood cells production of free radicals increasing the number of red blood cells

Alpha particles have little penetrating power in comparison to gamma rays

Alpha emitters are much less likely to cause damage to tissue than gamma emitters are. Why are most alpha emitters less dangerous to living systems than gamma emitters are?

16 days

Bismuth-210 has a half-life of approximately 8 days. How long will it take for a 64-mg sample to decay to 16 mg?

2.87 x 10^4 years

Carbon-14 has a half-life of 5730 years. In a plant fossil, you find that the 14C has decayed to 1/32.0 of the original amount. How long ago was this plant alive?

smoke detectors, nuclear power plants, nuclear weapons

Identify the uses of nuclear fission: smoke detectors nuclear power plants nuclear weapons increasing red blood cell count

1/0 n

In 1932, James Chadwick discovered a new subatomic particle when he bombarded beryllium-9 with alpha particles. One of the products was carbon-12. What particle did Chadwick discover?

206 82 Pb

In 2006, Soviet dissident Alexander Litvinenko was murdered when Polonium-210 was added to his tea; he died three weeks later. Polonium-210 is an alpha emitter. What other product is formed?

13 s

Krypton-81m is used for lung ventilation studies. Its half-life is 13 s. How long does it take the activity of this isotope to reach a half of its original value?

0.500 g

Phosphorus-32 has a half-life of 14.0 days. Starting with 8.00 g of 32P, how many grams will remain after 56.0 days ?

comes from many human and natural sources

Radioactivity in the environment...

masses, 235 UF6, 238 UF6, faster

The compounds 235UF6 and 238UF6 are separated by their atomic __________ and the speed at which their gas phase molecules move. ____________ is slightly lighter than _____________ and the separation is achieved by passing the gas through ta series of pinholes. The lighter one moves _________ and gradually outdistances the heavier isotope and is isolated (enriched).

fissionable, below, a single piece, explosion

The logic behind the design of the bombs was to keep several pieces of ___________ material, _________ their critical mass, separated from each other in the bomb. Then all the pieces would be forced together using an ordinary explosive, combining them into __ ________ ________ above the critical mass, thus triggering a runaway nuclear chain reaction and an ________________.

energy, together, binding

The missing mass is converted to __________ which is used to hold the protons and neutrons ______________ in the nucleus, it is referred to as the _____________ energy.

positron

The nucleon is unchanged; the atomic number decreases by 1

neutron

The nucleon number decreases by 1, there is no change in the atomic number

beta particle

The nucleon number is unchanged; the atomic number increases by 1

People can be nearby and live during the operation of a nuclear power plant, but they need be a long ways away during the operation of a nuclear bomb. Power plants use control rods to regulate the amount of neutrons and how much material is above the critical mass, bombs have no controls rods and the materials are all brought above the critical mass at once.

The same fission reaction is used for power plants that generate electricity and for atomic bombs. Determine some differences between the operation of a power plant and the explosion of a bomb.

one-fifth

What fraction of electricity in the United States is produced by nuclear power plants?

a neutron, an unstable, fission, released

What happens to the original 235U isotope during nuclear fission? 235U absorbs __ _________ to form ____ __________ 236U nucleus which then splits (undergoes _____________) to produce other elements and neutrons. This process causes lots of energy to be ______________.

radon

What source of natural background radiation contributes the most to our exposure?

neutrons

What type of particle keeps a chain reaction going?

uranium cosmic rays radon

Which of the following examples of radiation come from naturally occurring sources? uranium lasers nuclear power plants cosmic rays radon

visible light

Which of the following is not considered to be energetic enough to be ionizing radiation? ultraviolet light gamma rays x-rays visible light

iodine-131

Which radioisotope is commonly used to determine the size, shape, and activity of the thyroid gland?

alpha decay

Which type of radioactive decay produces a particle with a mass of 4 u and a charge of 2+?

gamma rays

Which type(s) of radiation has the highest penetrating power?

235U

Which uranium isotope undergoes fission and was used in the atomic bomb "Little Boy"?

3.0mg

A 48-mg sample of a radioisotope undergoes four half-lives. How much of the sample remains?