Chapter 8: Radioactivity Flashcards
Where was Henri Becquerel from?
France
What occupation did Henri Becquerel hold?
He was a physicist
Who was a French physicist who discovered radioactivity?
Henri Becquerel
What is Henri Becquerel responsible for the discovery of?
Radioactivity
What did Henri Becquerel study the effect of sunlight on?
Crystals of uranium salts
What did Henri Becquerel study the effect of on crystals of uranium salts?
Sunlight
How did Henri Becquerel accidently discover the radiation coming of off uranium salts?
(3)
- 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
What did Henri Becquerel find when he investigated the radiation being given off by uranium salts?
-he found the radiation was being emitted continuously and did not depend on factors such as light and heat
What does it mean if the radiation emitted by uranium salts is spontaneous?
(2)
- 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
What can uranium salts be described as?
-radioactive
What two colleges of Becquerel investigated the radioactivity of uranium salts in more detail?
-Pierre and Marie Curie
During their further investigation of the radioactivity of uranium salts, what did Pierre and Marie Curie first have to obtain?
-eight tonnes of an ore of uranium called pitchblende
What is pitchblende?
-an ore of uranium
What ore of uranium was used in Marie and Pierre Curie’s investigation of the radiation of uranium salts?
-pitchblende
What did the Curie’s isolate polonium and radium from?
-an ore of radium called pitchblende
What did the Curie’s do to the pitchblende in order to isolate the elements polonium and radium?
-they purified and re-purified the pitchblende into smaller and smaller samples of highly radioactive material
What is the process of purifying and re-purifying called that takes place in the isolation of polonium and radium from pitchblende?
-recrystallisation
What two new elements did the Curie’s isolate form pitchblende after thousands of recrystallizations?
-polonium and radium
What element number is polonium?
-element number 84
What element number is radium?
-element number 88
What element is element number 84?
-polonium
What element is element number 88?
-radium
Who shared the noble prize in physics in 1903 for their studies of radioactivity?
-Pierre and Marie Curie shared the noble prize with Becquerel
Who was awarded the Nobel prize in chemistry in 1911?
-Marie and Pierre Curie but Marie had to accept it alone as Pierre had passed away
