Atoms and Isotopes

Question 1

What is at the centre of every atom?

Answer 1

A nucleus

Question 2

What is contained in the nucleus of an atom?

Answer 2

Protons and Neutrons

Question 3

Describe an electron.

Answer 3

They are negatively charged, really, really small and whizz around the outside of an atom. Their paths take up a lot of space, giving the atom its overall size (though its mostly empty space).

Question 4

What is the number of protons in a nucleus called?

Answer 4

Atomic number

Question 5

What is the total number of protons and neutrons in the nucleus called?

Answer 5

Mass number

Question 6

What is the charge of a proton?

Answer 6

Positive

Question 7

What is an isotope?

Answer 7

Isotopes are atoms with the same number of protons (atomic number) but a different numbers of neutrons (mass number).

Question 8

How many stable isotopes do elements usually have?

Answer 8

One or two

Question 9

When is an isotope radioactive?

Answer 9

When the nucleus is unstable, so it decays (breaks down) and emits radiation.

Question 10

Name a stable isotope

Answer 10

Carbon-12

Question 11

Name an unstable isotope

Answer 11

Carbon-14