P4 - Radioactivity

What is a radioactive isotope?

An isotope with an unstable nucleus that emits radiation to become more stable

What is radioactive decay?

The process where an unstable nucleus emits radiation to become more stable

Is radioactive decay predictable?

No, it is a completely random process

What does "random" mean in radioactive decay?

Scientists cannot predict exactly when a nucleus will decay

What is activity in radioactivity?

The rate at which unstable nuclei decay in a radioactive source

What is the unit of activity?

Becquerel (Bq)

What does 1 Bq mean?

One decay per second

How can we measure the activity of a radioactive source?

Using a Geiger-Müller (GM) tube

What is the count rate?

The number of decays detected per second by a detector such as a GM tube

Is count rate the same as activity?

No, because background radiation can affect the count rate

What are the 4 types of nuclear radiation?

Alpha particles, beta particles, gamma rays, and neutrons

What is an alpha particle made of?

2 protons and 2 neutrons (same as a helium nucleus)

What is a beta particle?

A high-speed electron ejected from the nucleus

How is a beta particle formed?

When a neutron changes into a proton and an electron, the electron is emitted as a beta particle

Does the nucleus normally contain electrons?

No, electrons are not normally found in the nucleus

What is a gamma ray?

A type of electromagnetic radiation emitted from the nucleus

Is gamma radiation a particle?

No, it is a wave (electromagnetic radiation)

What is a neutron (as nuclear radiation)?

A neutron emitted directly from the nucleus of an atom

Which type(s) of radiation are particles?

Alpha particles, beta particles, and neutrons

Which type(s) of radiation are electromagnetic waves?

Gamma rays

Why do unstable nuclei emit radiation?

To become more stable