Chapter 8: Radioactivity

Question 1

Where was Henri Becquerel from?

Answer 1

France

Question 2

What occupation did Henri Becquerel hold?

Answer 2

He was a physicist

Question 3

Who was a French physicist who discovered radioactivity?

Answer 3

Henri Becquerel

Question 4

What is Henri Becquerel responsible for the discovery of?

Answer 4

Radioactivity

Question 5

What did Henri Becquerel study the effect of sunlight on?

Answer 5

Crystals of uranium salts

Question 6

What did Henri Becquerel study the effect of on crystals of uranium salts?

Answer 6

Sunlight

Question 7

How did Henri Becquerel accidently discover the radiation coming of off uranium salts?
(3)

Answer 7

• he left some uranium salts resting on a photographic plate wrapped in black paper in the darkness of a drawer in his desk
• He found that the photographic plate had become “fogged” or darkened in the area near the uranium salt
• The radiation given off by the uranium was penetrating the black paper and was affecting the photographic plate

Question 8

What did Henri Becquerel find when he investigated the radiation being given off by uranium salts?

Answer 8

-he found the radiation was being emitted continuously and did not depend on factors such as light and heat

Question 9

What does it mean if the radiation emitted by uranium salts is spontaneous?
(2)

Answer 9

• the emission of radiation was a property of the uranium itself and occurred naturally
• the radiation did not need light or anything else to cause it to emit the radiation

Question 10

What can uranium salts be described as?

Answer 10

-radioactive

Question 11

What two colleges of Becquerel investigated the radioactivity of uranium salts in more detail?

Answer 11

-Pierre and Marie Curie

Question 12

During their further investigation of the radioactivity of uranium salts, what did Pierre and Marie Curie first have to obtain?

Answer 12

-eight tonnes of an ore of uranium called pitchblende

Question 13

What is pitchblende?

Answer 13

-an ore of uranium

Question 14

What ore of uranium was used in Marie and Pierre Curie’s investigation of the radiation of uranium salts?

Answer 14

-pitchblende

Question 15

What did the Curie’s isolate polonium and radium from?

Answer 15

-an ore of radium called pitchblende

Question 16

What did the Curie’s do to the pitchblende in order to isolate the elements polonium and radium?

Answer 16

-they purified and re-purified the pitchblende into smaller and smaller samples of highly radioactive material

Question 17

What is the process of purifying and re-purifying called that takes place in the isolation of polonium and radium from pitchblende?

Answer 17

-recrystallisation

Question 18

What two new elements did the Curie’s isolate form pitchblende after thousands of recrystallizations?

Answer 18

-polonium and radium

Question 19

What element number is polonium?

Answer 19

-element number 84

Question 20

What element number is radium?

Answer 20

-element number 88

Question 21

What element is element number 84?

Answer 21

-polonium

Question 22

What element is element number 88?

Answer 22

-radium

Question 23

Who shared the noble prize in physics in 1903 for their studies of radioactivity?

Answer 23

-Pierre and Marie Curie shared the noble prize with Becquerel

Question 24

Who was awarded the Nobel prize in chemistry in 1911?

Answer 24

-Marie and Pierre Curie but Marie had to accept it alone as Pierre had passed away

Question 25

How many types of radiation is there?

Answer 25

three

Question 26

What are the three types of radiation?

Answer 26

• alpha particles
• beta particles
• gamma radiation

Question 27

How were the three different types of radiation discovered?

Answer 27

-by studying the behaviour of the radiation in electric and magnetic fields