# Part I - Radiation Physics - The Structure of Things

## 34 terms · Page 1 - 13 of Ekstrands Physics for Residents

10^-13 cm

10-8 cm.

### Each orbital in an atom has a specific energy of interaction associated with it, the ________ , and a discrete level called a _____________

binding energy

energy quantum number n (n = 1,2,3 . . .).

Lower, More

angular momentum

opposite spins

l, ml

Shape

2

### The group of orbitals having the same energy quantum number (and therefore approximately the same binding energy) is called a ______. The lowest energy shell (n=1) is called the __ ____. Next is the __ _____ (n=2), then come M, N, etc.

The group of orbitals having the same energy quantum number (and therefore approximately the same binding energy) is called a shell. The lowest energy shell (n=1) is called the K shell. Next is the L shell (n=2), then come M, N, etc.

### binding energies are +/- numbers, with the lowest level being the smallest/greatest in absolute magnitude. The unit of binding energy is ____ an electron w/a binding energy of 0 is _____

-

greatest

eV

just barely free of an atom

### One eV is the amount ________

One eV is the amount of energy an electron gains in crossing a potential difference of 1 volt (e.g., from a 1 volt battery).

### Hydrogen is the simplest of atoms, having ____ electron orbiting the nucleus.

Hydrogen is the simplest of atoms, having only one electron orbiting the nucleus.

### For atoms with many electrons, each shell with an energy quantum number n can have a maximum of ____ electrons.

2n^2

For example, the L shell can have 8 electrons, the M shell can have 18, etc. The lowest energy levels are always filled first.

### Ionization physically means

That an energy sufficient to remove an electron from an atom has been supplied resulting in an ejected electron and a positively charged ion

### If an electron jumps from a higher energy level to a lower one (_______ or _________), the atom gives off the excess energy, frequently in the form of _________ _________

If an electron jumps from a higher energy level to a lower one (de-excitation or relaxation), the atom gives off the excess energy, frequently in the form of electromagnetic radiation.

### In free space the velocity of all electromagnetic (em) radiation is____, designated as __. ___ = 3 x 10^8 meter/second.

In free space the velocity of all electromagnetic (em) radiation is a constant, c. c = 3 x 108 meter/second.

inversely

### Quantum theory asserts that all em radiation is transmitted in discrete energy units called _____ or _____. The energy of an individual photon is related to the wave frequency according to E = ______

Quantum theory asserts that all em radiation is transmitted in discrete energy units called quanta
or photons. The energy of an individual photon is related to the wave frequency according to
E = hv or E = hc/λ

h = 4.14x10^-15 ev/sec

### For X rays, wavelength is in units of ____, and the relationship of E (KeV) = ________

E (KeV) = 12.4/λ (angstroms)

### A free radical is a molecule (usually electrically neutral) with an ___ ____. A free radical is very reactive chemically and usually has a long/short half life, but is shorter/longer lived than an ion. Free radicals are produced by ionizing radiation.

A free radical is a molecule (usually electrically neutral) with an unpaired electron. A free radical is very reactive chemically and usually has a short half life, but is longer lived than an ion. Free radicals are produced by ionizing radiation.

### A nuclide (= _______ ) is represented by: A Z X where: X = Chemical symbol A = Z =

species of atom with a specific number of neutrons and protons

X is the chemical symbol
A is the atomic mass number (the number of neutrons + protons)
Z is the atomic number (the number of protons)

### As Z increases, the K shell binding energy increases in proportion to ____

As Z increases, the K shell binding energy increases in proportion to Z^2

### If an atom with a high Z is excited by an high energy (external) electron, a vacancy can be created in the K or L shell. An outer electron will fill the vacancy and a photon with energy in the X-ray region is created. The photon energy is equal to the difference of the two energy levels and is characteristic of the particular atomic species involved (hence the designation) The X ray created from that atom is called ______ and is specific to that type of atom

Characteristic X-rays
If an atom with a high Z is excited by an high energy (external) electron, a vacancy can be created in the K or L shell. An outer electron will fill the vacancy and a photon with energy in the X-ray region is created. The photon energy is equal to the difference of the two energy levels and is characteristic of the particular atomic species involved (hence the designation)

### Isobars -

nuclides with the same A but different Z,
isob"a"r = same "a"tomic number

e.g.,
27
Co
60

and

28
Ni.
60

### Isotopes -

nuclides with the same Z (protons) but different A.
Isoto"p"e = same "p"roton #
(These atoms are chemically the same but may have different nuclear properties),
e.g.,
8
O
16

and

8
O
15

### Isotones -

same number of neutrons (A - Z) but different Z, e.g.,
Isoto"n"es = Same "n"eutron #
13
Al
27

and

14
Si
28

### Isomers -

same A, same Z, but different internal nuclear energy, different configuration of the neutrons and the protons,

e.g.,
43
99Tc

and

43
99mTc

### Because the mass of an atom is so small, we frequently measure it in units other than kilograms. One unit is the_______, is set to equal _________ which has a mass number A = 12 (6 protons and 6 neutrons). In more common units 1 =

atomic mass unit, AMU

1/12 of a carbon atom

1amu=1.66 x 10-27 kg.

### If E = mc^2 and mass is in AMU then Energy (MeV) = _____

Energy(MeV) = 931 x mass(AMU)

e.g.
Mass (AMU) Mass (MeV)
Electron 0.00055 0.51
Proton 1.00727 938
Neutron 1.00866 939

### energy that is released when the particles which were bound together are disrupted =

Nuclear Binding Energy

### For light nuclides (Z < 20), the most stable configuration occurs when the number of neutrons is approximately less than/greater than/equal to the number of protons For heavier nuclides, stability occurs when the number of neutrons is less than/greater than/equal to the number of protons.

For light nuclides (Z < 20), the most stable configuration occurs when the number of neutrons is
approximately equal to the number of protons. For heavier nuclides, stability occurs when the
number of neutrons is greater than the number of protons.

### Nuclides in which A is an even/odd number and A - Z is also an even/odd number tend to be most stable.

Nuclides in which A is an even number and A - Z is also an even number tend to be most stable.

### In terms of evenness of the numbers, the stability varies as follows: Proton # Neutron # Most stable __ ____ Equally ___ ___ stable ___ ____ Least stable ___ ___ Bismuth (Z = 83) is the stable nuclide with the highest Z.

In terms of evenness of the
numbers, the stability varies as follows:
Proton # Neutron #

Most stable even even
Equally even odd
stable odd even
Least stable odd odd

Bismuth (Z = 83) is the stable nuclide
with the highest Z.

### What are the 4 fundamental forces known in nature according to strength

Gravitation<weak nuclear<electric/magnetic<strong nuclear

### beta decay is which type of the fundamental forces of nature

weak nuclear force

### What does the "mass defect" seen in atoms like deuterium represent

binding energy of the nucleus