Uranium-235 has 92 protons. How many neutrons does it have?
143
92
235
What are isotopes of an element?
Nuclei with the same number of protons but different number of electrons
Nuclei with the same number of protons but different number of neutrons
Nuclei with the same number of neutrons but different number of protons
What is gamma radiation?
An electromagnetic wave
A helium nucleus
An electron
Which form of radiation has the greatest ionising ability?
Alpha
Beta
Gamma
Which particle has an ionised atom lost?
Proton
Electron
Neutron
What is an alpha particle?
Which energy level in an atom is the lowest?
The one furthest from the nucleus
The one nearest the nucleus
The one in the middle
What is name of the process by which an electron moves to a higher energy level in an atom?
Excitation
Fluorescence
Ionisation
Which statement about the radioactive decay of an atom is correct?
It is predictable
It is random
It sometimes follows a pattern depending on the radiation type
What fraction of a radioisotope is left after two half-lives?
One quarter
One half
One eighth