P7.3 Changes in the nucleus

Question 1

What is the atomic number?

Answer 1

Is the number of protons inside the atom

Question 2

What is the mass number?

Answer 2

The number of neutrons and protons

Question 3

What are isotopes?

Answer 3

Atoms of the same element with different number of neutrons

Question 4

What is an alpha particles made up of?

Answer 4

A helium nucleus - 2 protons and 2 neutrons

Question 5

What happens when an unstable nucleus emits an alpha particle?

Answer 5

Atomic number goes by 2 and mass number goes down by 4

Mass and the charge of the nucleus are both reduced

Question 6

What is a beta particle?

Answer 6

An electron

Question 7

How is a beta particle created?

Answer 7

A neutron in the nucleus changes into a proton and a b particle is released

Question 8

What happens when an unstable nucleus emits B particle?

Answer 8

Atomic number of the nucleus goes up by 1

Charge of nucleus is increased - mass of the nucleus is unchanged

Question 9

What is an x-ray?

Answer 9

Is electromagnetic radiation from the nucleus of an atom - it is uncharged and has no mass

Question 10

How are neutron emitted?

Answer 10

By some radioactive substances such as alpha particles colliding with unstable nuclei