Lecture 3

Question 1

radiation

Answer 1

the emission or transmission of energy through space or a material medium
as either moving subatomic particles or electromagnetic waves

Question 2

two categories of radiation

Answer 2

non ionizing
ionizing

Question 3

ionizing radiation

Answer 3

radiation with sufficiently high enough energy that it can ionize an atom
able to knock electrons off atoms
results in a positive net charge
requires at least 10eV of energy

Question 4

Radionuclide identification

Answer 4

mode of decay (type and energy of radiation emitted)
decay scheme (how it decays)
rate of decay

Question 5

stable nuclides

Answer 5

nuclides with a neutron/proton ratio between 1 and 1.5 tend to be stable

Question 6

types of radiation

Answer 6

alpha decay
beta decay
positron emission
electron capture
gamma emission

Question 7

alpha decay

Answer 7

decreases the parent A by 4 and the parent Z by 2
occurs in radionuclides with a Z greater than 83

Question 8

A

Answer 8

atomic mass

Question 9

Z

Answer 9

atomic number

Question 10

alpha characteristics

Answer 10

radiation travels slowly
monoenergetic with very high levels of energy
play a role in therapeutic applications in nuclear medicine

Question 11

beta decay

Answer 11

occurs in imbalance between protons and neutrons
one of the excess p or n is converted into the other

Question 12

beta (minus) decay

Answer 12

unstable nuclei with excess neutrons
A stays the same, but Z increases by 1

Question 13

beta (minus) characteristics

Answer 13

-1 overall charge
travels slowly but not as slow as alphas
given off in a spectrum of energy levels with moderately high levels of energy
therapeutic applications

Question 14

beta (plus) decay

Answer 14

unstable nuclei with excess protons
A remains the same, Z decreases by 1
if not enough energy, electron capture occurs

Question 15

beta (plus) characteristics

Answer 15

positive 1 charge
also referred to as a positron and antimatter
convoluted path
does not exist for long in nature and will interact fairly quickly with an electron in the environment

Question 16

electron capture

Answer 16

process that also can occur in unstable nuclei with excess protons but not enough energy for positron emission to occur
nucleus captures one of its inner shell orbital electrons
A doesn’t change, Z decreases by 1
process results in a vacancy in the inner electron shell that must be addressed

Question 17

gamma decay

Answer 17

usually occurs after other forms of radioactive decay occur
no net change to the atom
relaxed nuclear state

Question 18

gamma characteristics

Answer 18

form of electromagnetic radiation
wavelength similar to light but more energetic
considered as bundles or packets of energy
travels at the speed of light
mono energetic with no spectrum of energies

Question 19

Xray vs Gamma

Answer 19

Xrays originate from electron shell while gamma originates from the nucleus via nuclear decay

Question 20

decay scheme

Answer 20

mode of decay of an isotope
can be used to identify a given radionuclide
determine the usefulness of a radionuclide - diagnostic use, therapeutic use, or no medical use
roadmap of what will happen

Question 21

decay scheme graph

Answer 21

proton number increases from left to right with arrows always going downward due to the removal of energy

Question 22

Q value

Answer 22

nuclear disintegration energy
amount of excess energy in the nucleus

Question 23

americium-241

Answer 23

key component of household smoke detectors as alpha particles given off ionie air molecules to create a constant flow between charged plates
when smoke enters, it disrupts flow signaling the alarm