L 2: Production and properties of radiation

Question 1

Neutron production

Answer 1

• is due to photodisintegration
• This results in change in atomic mass number but not the atomic number
• A is changed Z remains same

Question 2

Binding energy

Answer 2

• It is dependent on Z
• As Z increase the binding energy increases.
• It is due to coulombs interaction with nuclear protons.
• Electron binding energy is proportional to Z square.

Question 3

Chemical identity of the element is due to

Answer 3

Z
number of protons

Question 4

Characteristic X-ray production

Answer 4

• Otter shell electron descends to inner shell vacancy
• X-ray energy is = difference in binding energy of 2 shells.
• X-rays produced have discrete energy

Question 5

Auger electron production

Answer 5

• It can induce further damage in the organic macromolecues such as DNA

Question 6

Decay constant

Answer 6

Itis the reciprocal of the mean life and therefore has units inverse of time

Question 7

Half life of common isotopes

Answer 7

Americum-214 = 432 years
Cesium -137 = 30 years
Samarium-145 = 340 days ~ 1 year
Iridium-192 = 73.8 days
Iodine-125 = 59.4 days
Ytterbium -169 = 32 days
Palladium-103= 17 days
Gold-198 = 2.7 days