Atomic Structure

1) What is Radiation ?
This is the general term for any energy traveling through space as waves or particles,

2) What is Irradiation ?
The process by which an object is exposed to any type of radiation

3) What is Ionising Radiation ?
This is a specific, high-energy subset of radiation that can strip electrons from atoms.
There are three types:
Alpha - when an alpha particle is emitted from the nucleus
Beta - when a beta particle is emitted from the nucleus
Gamma - when a gamma ray is emitted from the nucleus

4) What is Ionisation ?
This is the removal (or addition) of an electrons (negative charge) from (or to) an atom.
There are two main types:
Positive ion - formed when an atom loses electrons
Negative ion - formed when an atom gains electrons

5) What is an alpha particle ?
2 protons, 2 neutrons
Nucleus of Helium
charge 2+
It has a mass of 6.645 x 10^-27 kg and a charge of +2.
Low penetration. Strong ionising

6) What is a beta particle ?
This is one electron (with high energy)
It has no mass and a charge of -1.
Medium penetration. Medium ionising

7) What is a gamma ray ?
This is a not a particle (with mass)
This is a wave of electromagnetic radiation.
It is pure energy released when an excited nucleus drops to a lower energy state.
High penetration. Weak ionising

8) What happens when a nucleus emits an alpha particle ?
The mass number (protons and neutrons) decreases by 4.
The atomic number (number of protons) decreases by 2.

9) What happens when a nucleus emits a beta particle ?
It undergoes beta decay.
This process involves a neutron transforming into a proton, an electron (the beta particle).
The electron is ejected from the nucleus at high speed, while the proton remains in the nucleus.
As a result, the atomic number of the nucleus increases by one, but the mass number (total number of protons and neutrons) remains the same.

10) What happens when a nucleus emits a gamma particle ?
The mass and charge remain unchanged.
No change in the atomic mass (protons + neutrons)
No change in the atomic number (number of protons)

11) What are Nuclear Equations ?
alpha
A > B + 4,2,He

beta
A > B + 0,-1,e

gama
nothing changes

12) What type of radiation is the most dangerous inside the body ?
Alpha radiation

13) What type of radiation is the same as a Helium Nucleus ?
Alpha radiation

14) What is the Half-Life of a radioactive source ?
The time it takes for half of the radioactive nuclei in a sample to decay,

15) What is the Activity of a radioactive source ?
The rate at which the decay occurs, measured in Becquerels (Bq).
where 1 Bq = 1 decay per second.

16) What are Nuclear Equations ?
These are used to represent radioactive decay

17) What is Net Decline ?
This is the term used to describe the overall decrease in a radioactive sample over time.

18) What happens during radioactive decay ?
number of unstable particles remaining decreases
Overall rate of decay (activity) also decreases

19) What equipment can you use to measure readiation ?
Geiger-Muller tube
Detects ionising radiation by allowing it to enter tube with gas
Creates electrical signal 4 every detection

Questions

20) How many different types of radiation are there ?

21) What determines how harmful radiation is and explain how ?
Type - ionising is the most dangerous (alpha, beta, gamma)
Quantity - how far away, how long, how radioactive
Exposure - outside the body, on the body, in the body

22) What is Contamination, when could it get dangerous ?
Radioactive particles get onto objects / humans
If the radioactive particles decay and irradiate - very dangerous

23) How do you measure the half life of a graph ?
Find initial activity (x = 0)
divide number by 2
draw intervals, between numbers
repeat with new number to see if first half life was right