Chemistry Quiz 2- Nuclear Chemistry

When electron capture occurs, the atomic number changes by…

Decreasing by 1

Nuclear reactions differ from chemical reactions by…

It is not affected by temperature or pressure changes, or the presence of catalysts

The final reaction of a series of spontaneous nuclear reactions is…

A stable isotope

What is the charge of gamma rays?

Zero

A beta particle is equal to…

An electron

What happens when an atom releases a beta particle and why?

The mass does not change because electrons have an almost non-existent mass

What happens when an atom emits a gamma particle and why?

The mass remains the same because gamma particles are 0,0

What is the least penetrating form of radiation?

Alpha radiation

What is the ionizing radiation that is identical to the helium atom?

Alpha radiation

When an atom emits an alpha particle, the mass…

Decreases by 2

When an atom emits a beta particle, the atomic number…

Increases by 1

What is likely to occur when the ratio of neutrons to protons is below the band of stability?

Positron emission

What does the alpha particle look like?

4,2 He

How does a positron different from an electron?

They have opposite charges

What decomposes to produce the electron of radiation?

Neutrons

What is the product of the decay if a nitrogen isotope decays by positron emission?

Carbon

What is necessary as a product of fission to establish a chain reaction?

Two or more neutrons

What does a neutron break down to form?

A proton and an electron

Why are spent fuel rods stored in a pool of water?

Water cools the rod and acts as a radiation shield

How many years does it take for the radioisotopes in rods to decay to safe levels?

Tens of thousands of years

When happens when an isotope decays by the process of beta emission?

The atomic number changes

How does an atom with too many neutrons relative to protons undergo radioactive decay?

By emitting a beta particle

What does the atomic number 18 changing to atomic number 19 mean?

It emitted a beta particle

What does emitting positron particles do?

It increases the neutron-to-proton ratio (emitting makes them decrease)

What does emitting beta particles do?

It decreases the neutron-to-proton ratio (emitting makes the atomic number increase)

What happens in positron emission?

A proton changes to an electron

Emission definition:

Atoms emit to release the these particles in order to get to a stable isotope

Decay definition:

The process of getting to a stable isotope is decay

A transmutation reaction must always involve…

A change in the number of protons in a nucleus of an atom

How does the radiation from radioisotopes cause damage to human tissue?

By ionization knocking electrons away from atoms

What particles maintain a nuclear chain reaction?

Neutrons

Controlled nuclear chain reactions…

Take place in nuclear reactors

What is commonly used to remove heat from a nuclear reactor core?

Liquid sodium

Fusion definition:

Smaller nuclei combining to produce a nucleus of greater mass

Fission definition:

The nuclei of certain isotopes are bombarded with neutrons causing the nuclei to split into smaller fragments

True or false. Nuclear fusion takes place in the sun

True

What does nuclear absorption accomplish in a nuclear reactor?

It slows the reaction

What is used in control rods to absorb neutrons in a nuclear power plant?

Cadmium

What are commonly used as neutron moderators (slow neutrons) in a nuclear reactor?

Carbon and water

_____ is commonly used to routinely check a person’s exposure to radiation over a period of time

A film badge

What is the main detector of a Geiger counter?

Ionizable gas in a metal tube

What is the main detector of a scintillation counter?

A phosphor covered surface

What do radioisotopes do in radiation therapy?

They kill fast-growing cells

Why should a tracer be used to detect only beta and gamma rays in humans?

Alpha radiation cannot penetrate the skin

How are radioactive isotopes used to diagnose thyroid problems?

Uptake of radioactive iodine by the thyroid gland is measured

Above which atomic number are the nuclei radioactive?

82

How to make the things fractions in equations?

1/2^half life or n

Remember in equations:

Flip

What is the ratio for stable isotopes of neutrons to protons?

1:1