RADIOACTIVITY

Question 1

what is the atom made up off?

Answer 1

neutrons, protons in a nucleus with orbiting electrons in the outer shell.

Question 2

what is the difference between the way gamma rays are made and the way radio waves are made? [6 marks]

Answer 2

Radio;
- produced intentionally
- produced by free electrons
- produced in electrical circuits
Gamma:
- randomly produced
- result in radioactive decay
- produced in nucleus
- result of nuclear fusion or fission or PET scanning

Question 3

How is a graphite core and moveable rods used to maintain and control the chain reaction?

Answer 3

• neutrons released
• slow neutrons needed for fission
• neutrons are fast
• control rods control the speed of reaction
• moveable rods absorb neutrons
• graphite core is the moderator
• graphite slows the neutrons

Question 3

How can you detect radiation?

Answer 3

GM tube
photographic film

Question 4

what did Rutherford discover in his gold foil experiment?

Answer 4

1. the atoms is mostly empty space, as some alpha particles passed through the gold foil.
2. the nucleus has a positive charge, as some particles diverged away from the nucleus as two protons repel each other.

Question 5

How to work out the half life of a radioactive sample.

Answer 5

Keep halving the original mass of the substance until you get to the end time
the number of time the mass is halved divided by the time.

Question 6

how to find the proportion of a sample when given the half life.

Answer 6

find how long the time is and find how many half lives fit into it.
half 100% that amount of times.