More about radiation pt 2

Question 1

What is the intensity of the radiation?

Answer 1

radiation energy per second passing normally through unit area

Question 2

What is the equation for the intensity of radiation at r? using n as the number of gamma photons per second

Answer 2

= radiation energy per second / total area

= nhf / 4πr²

Question 3

What does this say about the intensity?

Answer 3

intensity varies with the inverse square distance r

Question 4

What happens to the atomic number and mass number due to alpha emission?

Answer 4

• A = -4
• Z = -2
• (a = mass number, z = atomic number)
• ^A_ZX → ⁴₂α + ^A-4_Z-2Y

Question 5

What happens to the atomic number and mass number due to beta- emission?

Answer 5

A = 0

Z = +1

^A_ZX → ⁰_-1β + ^A_Z+1Y + ^–Ve^–

Question 6

What happens to the atomic number and mass number due to beta+ emission?

Answer 6

^A_ZX → ⁰₊₁β + ^A_Z-1Y + V_e

Question 7

What happens to the atomic number and mass number due to gamma emission?

Answer 7

no change

it is emitted if a nucleus has excess energy after it has emitted an alpha or a β- particle

Question 8

What is electron capture?

Answer 8

• proton rich nuclides can capture an inner-shell electron
• this causes a proton in the nucleus to change into a neutron
• with the emission of an electron neutrino
• the inner shell vanancy is filled by an outer-shell eelctron
• as a result causing an x-ray photon to be emitted by the atom

Question 9

What is the equation for electron capture?

Answer 9

^A_ZX + ⁰_-1e → ^A_Z-1Y + V_e