Nuclear Chemistry Quiz

When does radiation occur?

when the ratio between protons and neutrons in the nucleus of an atom is imbalanced

How does the nueclus become balanced?

it emits matter and/or energy (this is called radiation)

What does radiation result in?

a stable nucleus

Alpha particles

• have the same makeup of a helium nucleus

• largest mass

• weakest penetrating power

beta negative particles

• same as an electron with negligible mass and -1 charge

• small mass and medium penetrating power

beta positive particles (positron)

• positive charge

• same penetrating power and size as beta negative

gamma particles

• only nuclear energy

• no mass

• most penetrating power

How to fill in missing pieces of nuclear reactions

• algebra

• the sum of the numbers on top should be equal

• same for the bottom

Nuclear reactions

when a small amount of matter is converted into a very large amount of energy

Eistein’s equation

e = mc²

Loosened version of the law of conservation

matter and energy are different forms of the same thing and can change between forms

Natural transmutation

spontaneously changing an atom of one element into a different element

How do radioisotopes become stable over time?

natural transmutation

Artificial transmutation

a scientist bombards a nucleus with a high energy particle such as a neutron or an alpha particle in a lab

Fission

a large nuclei is split into middleweight nuclei and neutrons. This is used for nuclear power

Fusion

light nuclei combine to form heavier ones. This reaction is how the elements were made in stars

Tracer

a radioactive atom (or a few) that can be easily found in scans

How do we use tracers?

in chemical reactions we use them to track specific atoms’ movements. In medical scans we use tracers to read MRIs or X-Rays.

Iodine-131

can be used in diagnosing. and treating thyroid disorders

Thyroid

gland in the neck that helps t regulate sleep and metabolism

Carbon-14

can be used to date once-living organisms in a proess called carbon dating.

uranium-238

can be used to date geological formations or rocks. uses the ratio between U-238 and Pb-206

Cobalt-60

can be used to treat some cancers

Americicium-241

can be used in smoke detectors. The radioisotope releases alpha particles which flow through the detector, and the detector goes off when smoke abrupts the flow

Half life

the amount of time neeed for half of a radioactive substance to decay

chain reaction

self-propagating reaction—the materials that start the reaction are also one of the products and starts another reaction

How is chain reaction prevented in a nuclear reactant?

the chain reaction is kept under control by the use of control rods. Neutron-absorbing control rods keep the system from reaching critical mass by limiting the number available nuetrons

critical mass

mass required to sustain a reaction

Describe Fission

• uranium-238 limited supply

• danger of meltdown

• toxic waste

• thermal pollution

Describe fusion

• fuel is abundant

• no danger of meltdown

• no toxic waste

• not yet sustainable

compare fission and fusion

• fusion needs 10^7K to start reaction while fission needs 1000K

• Fission releases 2.1×10^12J/g energy while fusion releases 3.4×10^14J/g