Physics Quiz 3 - Atomic Physics

What is the unit of exposure in air?

Roentgen

What is the unit of electrical charge?

Coulomb

1 Roentgen = ...?

2.58 x 10^-4 C/kg

What is the unit of absorbed dose?

Gray

How many cGy in 1 Gray?

100 cGy

1 Rad = ....cGy?

1 cGy

What do you use to convert Roentgens into centiGrays?

The f Factor

What is the f Factor affected by?

Density of irradiated material and Beam Energy

f Factor Equation

Dose (in Gray) = Exposure (in Roentgen) x f Factor (of irradiated material)

What is the smallest unit of an element that retains the property of that element?

an Atom

What is an atom composed of?

Protons, Neutrons, Electrons

What are nucleons?

Protons and Neutrons

Protons and Neutrons are located in?

The nucleus

What charge do protons have?

Positive charge

What charge do Neutrons have?

NO charge

What charge do Electrons have?

Negative charge

What are photons?

Packets of electro-magnetic energy

Do photons have resting mass or charge?

No

Bohr Atomic Model states

Electrons surround the nucleus in different energy states/orbits

T/F: Electrons lose energy while in orbit

False; electrons do not lose energy

What is the atomic spectra?

The energy emitted when electrons move from higher to lower energy orbits. They emit energy in the form of radiation

T/F: It takes little energy to hold the nucleus together

FALSE; It takes a lot of energy to hold nucleus together

T/F: The atom is mostly empty space

True

How to calculate the max number of electrons in a shell?

2n^2, where n = shell number

What number shell is Shell K?

The first electron shell (the innermost shell)

What number shell is Shell L?

Shell 2

What number shell is Shell M?

Shell 3

The charge of an ATOM depends on whether there are....?

MORE or LESS electrons than protons

What is the overall atomic charge if of an atom that has 6 protons and 7 electrons?

The overall charge is Negative

What are the 4 Fundamental Forces of Nature? (in order of weakest to strongest)

1. Gravitational Force
2. Weak Nuclear Force
3. Electromagnetic Force
4. Strong Nuclear Force

What fundamental force of nature is the weakest?

Gravitational force

Gravitational force has _____________ range

Infinite

Weak Nuclear Force has __________ range

Short

Electromagnetic Force has __________ range

Infinite

Strong Nuclear Force has __________ range

Short

Which fundamental forces have infinite range?

Gravitational and Electromagnetic Forces

Which fundamental forces have short range?

Weak Nuclear and Strong Nuclear Forces

Which Forces are familiar from every day life?

Gravitational and Electromagnetic Forces

Why are the Weak and Strong Nuclear Forces not familiar to every day life?

They manifest on a microscopic scale

What is Gravity?

The force that attracts an object toward the center of the earth

Electromagnetic Forces binds ___________ & the ___________________ to form an atom

Electrons and the Nucleus

Electromagnetic Forces binds ___________ to form Molecules

Atoms

What is formed from binding atoms and molecules?

Liquids and Solids

What do Strong Nuclear Forces do?

They hold Protons and Neutrons together in the nucleus

What are Weak Nuclear Forces responsible for?

Radioactive Beta Decay

What is Beta Decay

The atomic nucleus emits a beta particle (an electron or positron), transforming into an Isobar

What is a Beta Particle?

Electrons or Positrons that are emitted from radionuclides during Beta Decay

What is an IsobAr

A Radionuclide with the same A value (number of Nucleons), but different Z value (number of Protons)

The A in atomic notation represents?

The Atomic MASS Number
- Number of Protons + Number of Neutrons

The Z in atomic notation represents?

The Atomic Number
- Number of PROTONS ONLY

The X in atomic notation represents?

The Chemical Symbol

What are isotoPes?

An atom of the same element with the SAME # Protons but DIFFERENT # neutrons

What is an Isomer?

2 Atoms with the same A and Z values but in a DIFFERENT ENERGY STATE

What type of state is an Isomer in?

An excited state

What is an IsotoNe

2 Atoms with the same number of Neutrons

Another word for Different Energy State is?

Metastable

Metastable means

Slight margin of stability

What is the Nucleus Binding Energy?

The total amount of energy needed to hold a nucleus together
OR
Minimum energy needed to separate the protons and neutrons

What is Binding Energy measured in?

Mega-Electron Volts (MeV)

What are the 6 atomic energy levels

1. Electron Binding energy
2. Valence Electrons
3. Excitation
4. Ionization
5. Characteristic X-Rays
6. Auger Electrons

What is Electron Binding Energy??

The energy needed to remove an electron from the orbit

What are Valence Electrons?

Electrons in the outermost shell of an atom

What are valence electrons responsible for?

Chemical reactions and atom interactions

What is Excitation?

The process where electrons gain energy and move to a higher energy state

The close electrons are to the nucleus, the _____________ the energy level

Lower

What is Ionization?

The removal of electrons

- Enough energy given for e- to overcome their binding energy and leave the atom

What are characteristic X-rays?

The emission of excess energy in Photons when a vacancy in the inner electron shell is caused by either Ionization or Excitation

What are Auger electrons?

When a vacancy in the inner shell is filled by an electron in an outer shell AND another outer shell e- is ejected from the atom

Auger Electrons are a secondary effect of ______________ ___________.

Characteristic X-rays

Radioactivity Definition

Emission of energy in the form of EM radiation or energetic particles from the nucleus in attempt to return to GROUND STATE ENERGY

Ground State is?

The minimum amount of energy needed to keep nucleons together

Ground state is equivalent to ___________

stable

What is Brachytherapy?

Placement of RAM inside or on the surface of a patient's body

What is External Beam Therapy (Teletherapy)?

Use RAM to make a beam that is applied externally to the patient