Radioactivity

Question 1

Describe Alpha emission [3]

Answer 1

> cluster of 2 protons and 2 neutrons (+ve charge)
can be stopped by a sheet of paper
when an atom decays by it, it’s 2 places to the left in PT

Question 2

Describe Beta Emission [3]

Answer 2

> Fast moving electrons (-ve charge)
stopped by 0.5cm aluminium
when an atom decays it’s 1 place right in the PT

Question 3

Describe Gamma emission [2]

Answer 3

> high energy electromagnetic radiation (no charge)

>stopped by 2cm of lead

Question 4

Describe radioactivity in living cells

Answer 4

> high energy radioactive emissions break chemical bonds in the cell molecules giving rise to changes in DNA
this causes mutations and the formation of cancer cells at lower doses and cell death at higher doses

Question 5

Give uses of radioactivity

Answer 5

> MEDICINE : cobalt 60 in radiotherapy treatment of cancer cells. Gamma rays kill the cancer cells
RADIO DATING : carbon 14 used to calculate the age of plant and animal remains