Decay

Question 1

Isomeric transition

Answer 1

Nucleus is excited (isomeric) state and goes from higher energy to lower energy. The extra energy in the nucleus is released by a gamma ray, returning the nucleus to ground state.

Long excited states = “meta”

Question 2

Electron capture

Answer 2

In atoms where nucleus has smaller neutron:proton ratio

Inner shell electron is captured and electrons move down to fill spots

Makes characteristic X-rays

Question 3

Beta decay B-

Answer 3

Nucleus is neutron rich.

A neutron transforms itself into a proton by releasing an energetic electron (beta particle) + an antineutrino

Question 4

Neutrino

Answer 4

Particle with no electric charge and negligible mass but its energy motion balances the energy of the reaction

Question 5

Atomic number decreased by two (-2)

Answer 5

Alpha decay

Question 6

Atomic number increased by one (+1)

Answer 6

Beta decay

Question 7

Atomic number decreased by one (-1)

Answer 7

Beta B+ (positron) decay

Or

Electron capture

Question 8

No change in atomic number

Answer 8

Gamma emission

Question 9

Beta decay can produce what kind of interaction?

Answer 9

Bremsstrahlung

Question 10

Positron or B+ decay

Answer 10

Proton rich atoms

Proton transformed into a neutron by emitting a B+ particle + a neutrino

1.02 MeV needed to occur

Question 11

Alpha decay

Answer 11

Heavy nuclei decays by alpha

Alpha particle is a helium ion with 2 electrons stripped off and contains 2 protons and 2 neutrons bound together

Question 12

Standard deviation (1, 2, 3)

Answer 12

Indicates the precision of the measurement. SD=sqr. of mean count

1 SD = 68%
2 SD = 95%
3 SD = 99%