Radioactivity Pt. 2 Flashcards
What is thermonic emission?
When negative particles (electrons) are released from a cathode
What was the initial hypothesis of the structure of an atom ?
The plum pudding model
What did Rutherford propose in 1911?
That the atom had a positively charged core (nucleus)
How much available space does the nucleus take up ?
A very small amount
What is an atoms atomic number ?
Number of protons + neutrons
What is an atoms mass number ?
Number of protons
What is different and the same about an isotope of an atom ?
Same atomic number different mass number
As the nucleus gets heavier, what happens to the ration of neutrons to protons?
It increases
Why do some nuclei fall within the belt of stability ?
Their n:p ratios are either too low or too high
Describe the decay of an atom
Decay is spontaneous and random
Give an industrial use of radiation
Beta radiation can be used to monitor thickness of paper and aluminium
Must all nuclear equations be balanced ?
yes
What is count rate measured in ?
Disintegrations per second
What can be used to measure count rate ?
GM tube
What is the natural radiation in wood, rock and people called?
Background activity
