Unit 3- NUCLEAR CHEMISTRY Flashcards
What does alpha radiation consist of?
Two protons and two neutrons
Carry a double positive charge
What is alpha particles attracted to?
Negatively charged plate
what is the symbols for an alpha particle?
What is beta radiation attracted to?
Positively charged plate
In beta radiation what does the neutron break down to?
A neutron changes into a proton
What happens to the electrons in beta radiation?
Ejected from the nucleus of an atom
What is gamma radiation
Electromagnetic waves from the nucleus of an atom
What is gamma radiation attracted to?
nothing, not deflected by an electric field
What is the travel distance of alpha radiation and what can stop it?
few cm, it can be stopped by piece of paper
What is the travel distance of beta radiation and what can stop it?
over a meter in air stopped by sheet of aluminium
What is the travel distance of gamma radiation and what can stop it?
Great distance in air, stopped by barriers made of materials such as lead or concrete
What is a half life?
Time taken for the activity to decrease by half
What is the symbols for a beta particle?
Which particle will be formed when an atom of 239U emits a Beta particle?
239 Np
Which particle will be formed when an atom of 226Ra emits an alpha particle?
222Rn
A sample of Polonium-208 has a mass of 6g. It is a gamma-emitting radioisotope with a half life of 3 years.
Calculate the mass, in grams, of Polonium-208 that would be left after 15 years.
year 0 –> 6g
year 3 –> 3g
year 6 –> 1.5g
year 9 –> 0.75g
year 12 –> 0.375g
year 15 –> 0.1875g
A sample of Tungstem-185 has an original mass of 40g.
After 300 days, 2.5g of the sample is left.
What is the half life of Tungstem-185 ?
day 0 –> 40g
day ? –> 20g
day ? –> 10g
day ? –> 5g
day ? –> 2.5g –> 300days
300days / 4 = 75 days
