6.5 Helpful Radiation

Question 1

Radiotherapy

Answer 1

Using radiation such as X-ray or decaying isotopes to kill cancer cells in the body

Question 2

External vs Internal radiotherapy

Answer 2

External is radiation specifically targeted at cancer and blasts the cancer cell from all directions

Internal is placing radioisotopes inside the body at or near the site of cancer to kill cancer cells

Question 3

How does a smoke alarm work?

Answer 3

There are anode and cathode in the alarm, as well as a small amount of Americium-241 which emits alpha radiation. This ionises the nitrogen and oxygen in the air, forming ions which attach themselves to the charged plates and form an electric current.

When smoke reaches the detector, they attach themselves to the charged plates, which neutralises the plates and disrupts the current. This makes the siren sound.

Question 4

How does PET scan work?

Answer 4

Radioisotopes absorbed by the tumour emit gamma rays, unlike normal cells. These radiation emitted are detected by the PET scanner to produce hundreds of 2D slices, which are assembled to form a 3D model of the cancer

Question 5

How does food irradiation work?

Answer 5

Exposing food to gamma rays from cobalt-60 kills pests on fruits and vegetables, as well as bacterias. It preserves food longer since it kills moulds and yeast, as well as slowing down the enzyme’s process of breaking down the food.

However, it can destroy the vitamins in the food.