OCR Gateway GCSE Physics A topic P6 Radioactivity overview quiz quiz

The number of neutrons in the nucleus

The total number of protons and neutrons

The number of protons in the nucleus

The number of electrons in the outer shell

Atoms of different elements that happen to share the same mass number

Atoms that have lost an electron and so carry an overall charge

Atoms that have no neutrons at all in their central nucleus

Atoms of the same element with different numbers of neutrons

Most of the atom is empty space with a small, dense, positive nucleus

The atom is a solid sphere of positive charge with no empty space inside

Electrons are spread out evenly all the way through the whole atom

The central nucleus of the atom carries an overall negative charge

Gamma

Alpha

Beta

X-rays

Atomic number falls by 2 and the mass number falls by 4 as well

Both the atomic number and the mass number stay exactly the same

Atomic number rises by 1, mass number is unchanged

Atomic number falls by 1 while the mass number rises by 1 instead

The time taken for the whole of the radioactive sample to fully decay away

Half of the total age of the radioactive source since it was first formed

The time taken for the radioactive source to become completely safe to handle by bare hand

The average time for half the undecayed nuclei to decay, or for the count rate to halve

200 counts per minute

800 counts per minute

400 counts per minute

100 counts per minute

They are really the same thing described using two different names for it

Irradiation is exposure from an outside source; contamination is radioactive material getting onto or into an object

Irradiation always makes an object become radioactive afterwards; contamination never does this at all to any object

Contamination can only ever happen with gamma radiation and never with alpha or beta

Two light nuclei joining right up together to form a single much heavier nucleus instead

An electron breaking free and leaving the nucleus of the atom

A large unstable nucleus splitting into smaller nuclei, releasing energy and neutrons

A nucleus absorbing a passing gamma ray and becoming more stable

To melt the nuclei together so they can flow and join up into one

To slow the nuclei right down so that they can join gently together

Because nuclear fusion needs a constant supply of plenty of oxygen in order to take place and keep going

Because the positively charged nuclei repel each other and must collide fast and close enough to fuse