Nuclear Energy: Year 10 Physics

Simple nuclear physics

Recall a description of the Bohr’s model of the atom

An atom has a central core consisting of protons and neutrons called the nucleus which contains all the mass of an atom. Small particles called electrons orbit the nucleus at very high speeds. Atoms have no charge

Define Nucleon

Any particle, proton or neutron found in an atomic nucleus

Define Strong Nuclear Force

The strong nuclear force is the strongest fundamental force that binds nucleons together, being attractive at 1–2 fm but repulsive below 0.5 fm to prevent nuclear collapse.

Electromagnetic Force

The electromagnetic force is the force between charged particles, responsible for attraction or repulsion.

Radioactive decay

Is where a nucleus is unstable and decays by emitting high energy alpha, beta particles or high energy gamma rays.

I can relate knowledge of strong nuclear force and (counters) electromagnetic force to the stability of nucleus.

Protons of like charges in the nucleus repel each other due to electromagnetic force. But strong nuclear force possesses a much stronger attractive force between nucleons at distances of 1-2 fm, preventing the coulomb repulsion of like positive charges. However, strong nuclear forces become repulsive at distances less than 0.5 fm, preventing collapse.

I can relate binding energy to stability of a nucleus and relate to nuclei becoming radioactive.

The binding energy of a nucleus is the energy that holds its protons and neutrons together — the higher the binding energy per nucleon, the more stable the nucleus is. If a nucleus has a low binding energy per nucleon, it is less stable and can break apart or change to reach a more stable state — this process is what makes a nucleus radioactive.

Describe alpha radiation

Due to too many protons and neutrons, an atom’s nucleus becomes unstable. The atoms emit an alpha particle consisting of 2 protons and 2 neutrons to become more stable.

Describe Beta radiation

When there are too many neutrons in a nucleus, a neutron is changed into a proton and an electron, making a more stable nucleus. The newly created electron shoots out of the nucleus at almost the speed of light. This is Beta particle. The proton remains in the nucleus.

Describe Gamma Radiation

An excited nucleus is unstable and release a gamma ray to obtain stability. Gamma rays from radioactive decay process result only in the de-excitation of a nucleus that is left in an excited state after alpha or beta decay. The isotope itself will not change.

Characteristics of Alpha particles

Heavy(4amu)

Speed = Low

Ionising ability = high (large size and strong charge easily knocks off electrons with collission)

Penetrating power = low (large so easily stopped)

Stopped by paper

Characteristics of Beta particles

Very light (1/2000 amu)

Speed = Very fast almost speed of light

Ionising ability = medium (because they are tiny)

Penetrating power medium (travel through cm or metres of air and few mm of own kin)

Stopped by Aluminium

Characteristics of Gamma particles