Chapter 8: Radioactivity

Question 1

Henri Becquerel

Answer 1

1) In 1896, while investigating uranium salts, Becquerel accidentally discovered radioactivity.
2) He found that photographic plates in contact with uranium salts emitted radiation.
3) Emission of the radiation was spontaneous.

Question 2

Marie and Pierre Curie

Answer 2

In 1898, Polish chemists Marie and Pierre Curie carried out more research on uranium salts.
- They called the radiation radioactivity.
- They isolated two new elements- polonium and radium.
- They are much more radioactive than uranium.

Question 3

Radioactivity

Answer 3

is the spontaneous breaking up of unstable nuclei with the emission of radiation.

Question 4

3 Types of radioactivity;

Answer 4

1) Alpha particles
2) Beta particles
3) Gamma rays

Question 5

What instrument is used to detect radiation?

Answer 5

The Geiger Muller Tube

Question 6

Alpha particles

Answer 6

are helium nuclei, with a positive charge and little penetrating ability.

Question 7

Beta particles

Answer 7

are electrons, with a negative charge, and a greater penetrating ability than alpha particles.