Nuclear Reactions

What is a nuclear reaction?

A process that involves changes to an atom's nucleus.

Often, this can change one element into another.

How are nuclear reactions different from chemical reactions?

Chemical reactions involve forming and breaking chemical bonds; they do NOT change the nuclei of atoms.

Nuclear reactions involve forming, breaking, or otherwise changing the nuclei of atoms.

What are the main kinds of radioactive decay?

1) Alpha decay

2) Beta decay

3) Gamma decay

What is alpha decay?

A form of radioactive decay wherein a nucleus emits an alpha particle (i.e., a helium nucleus, which has 2 protons and 2 neutrons)

Because the nucleus thereby loses two protons, this decay changes the identity of the original element.

What is the symbol for an alpha particle?

α, or see the image below:

What is beta decay?

A form of radioactive decay wherein a nucleus emits an electron (i.e., a beta particle).

This electron is created by splitting a neutron into a proton and an electron.

Because a proton is created in the process, this form of decay changes the identity of the original element.

What is the symbol for a beta particle?

β, or see image below:

What is gamma decay?

A form of radioactive decay wherein a nucleus emits an energy wave called a gamma ray.

Because they are waves and not particles, they do not change the identity of the original element.

What is the symbol for gamma decay?

γ, or see image below:

List the radioactive particles from least to most penetrative/damaging. Explain how you decided the order.

1) Alpha particles

2) Beta particles

3) Gamma rays

Alpha particles are the least penetrative because they are the most massive/bulky, so they can be blocked very easily.

Gamma rays are the most penetrative because they have no mass, so they cannot be blocked very easily.

What can you use to stop alpha particles?

Human skin or paper

What can you use to stop beta particles?

Aluminum foil

What can you use to stop gamma rays?

Thick pieces of lead or concrete

How can radiation be used to help people?

Radiation can be used to kill cancel cells, bacteria, and viruses, which saves many human lives.

What are the two main types of nuclear reactions?

1) Nuclear fission

2) Nuclear fusion

What is nuclear fission?

A nuclear reaction that involves splitting a nucleus into smaller pieces, which releases radiation and creates two new elements.

How can scientists stimulate nuclear fission in a lab?

By shooting neutrons like bullets at a nucleus.

What is nuclear fusion?

A nuclear reaction that involves combining two nuclei into one, which releases radiation and forms a new element.

What kind of environment is required for nuclear fusion to take place?

Temperatures of 100,000,000°C are needed.

This is not very practical to execute on Earth. The Sun, on the other hand, is able to maintain these temperatures for its fusion reactions.

What is nucleosynthesis?

The synthesis of new elements through nuclear reactions

What are nuclear equations? What things must be constant on both sides?

Use your knowledge to write the equation for the alpha decay of Barium-140

It is a symbolic way of representing nuclear reactions.

The sum of the mass numbers on both sides of the equation must be constant.

The same goes for the atomic numbers.

This is because the nuclear reactions must abide by the Law of the Conservation of Mass.

What is a parent isotope?

The initial isotope in a nuclear reaction

What is a daughter isotope?

The product isotope in a nuclear reaction

What is a nuclear chain reaction?

A process wherein triggering one nuclear reaction triggers surrounding reactions.