Radioactivity Flashcards
What does the nucleus of an atom contain?
Protons and neutrons - it make up most of the mass of the atom, but takes up very little space (tiny).
What is the atomic number?
The number of protons in the nucleus (also known as the proton number).
What is the mass number?
The total number of protons and neutrons in the nucleus (also know as the nucleon number).
What are electrons?
Tiny negatively charged particles which orbit the nucleus at high speeds. These paths take up a lot of space, giving the atom its overall size (though its normally empty space).
What are isotopes?
Atoms with the same number of protons but a different number of neutrons.
Name the most common isotope of carbon
Carbon-14 (2 more neutrons than normal carbon which has 12).
How many stable isotopes does each element usually have?
1 or 2 - the others tend to be radioactive
What is meant by a radioactive isotope?
The nucleus is unstable, so it decays and emits radiation.
Give an example of an unstable isotope of carbon?
Carbon-14
What is radioactive decay?
A random process by which the nuclei of unstable isotopes break down.
How does each nucleus decay?
Spontaneously and in its own time - it’s completely unaffected by physical conditions like temperature and or chemical bonding.
What does the nucleus release when it decays?
Alpha, beta, and gamma radiation (or neutrons)
What happens in the process of radioactive decay?
The nucleus often changes into a new element
Name 4 sources of background radiation
1) Air, food, buildings.
2) Cosmic radiation from space (mostly the sun).
3) Living organisms.
4) Radiation due to human activity e.g. nuclear waste and explosions (Chernobyl in 1987).
