Radiation Flashcards
What can be found at the centre of an atom?
The nucleus
What is a nucleus made up of?
Protons and Neutrons
Where are the electrons found in an atom?
In orbits around the nucleus
What is the atomic number?
Number of protons (and electrons) in an atom
It is always the smaller number!
What is the mass number?
Number of protons plus the number of neutrons
Helium has 2 protons and 2 neutrons so the mass number is 4
What is an ion?
An atom with some electrons added or removed to leave it with an overall positive or negative charge
What is an isotope?
Atoms with the same number of protons but a different number of neutrons
E.g. Carbon 12 (6 neutrons)
Carbon 13 (7 neutrons)
Carbon 14 (8 neutrons)
Name the 3 types of ionising radiation?
Alpha particles
Beta particles
Gamma rays
What is the half-life of a radiative source?
The average time it takes for half of the radioactive nuclei to decay
What is radioactive activity?
Number of nuclei that decay per second
