rad physics quiz 1 study

Electron binding energy depends on two things - what are they?

1. How close the electron is to the nucleus of the atom 2. Number of protons in the nucleus

What is the maximum number of electrons that the K shell can hold?

2

If an atom has 3 electrons, how are they distributed?

2 in the K shell 1 in the L shell

What is the formula used to determine how many electrons are located in a given shell?

2n^2

What is the formula which is used to determine how many electrons can occupy a particular orbit around the nucleus of the atom?

2n^2 (and n is the shells number, starting with K, which is number 1)

What is the maximum number of electrons which can be in the O shell of an atom, as long as it's not the outermost shell?

50 [The formula is 2n^2 and the O shell is the 5th orbital electron shell. 2(5)2 = 2(25) = 50.]

Why is it important for the radiology student to understand atoms?

> Interactions in the x-ray tube that produce x-rays occur at the atomic level > Interactions between the x-ray photons and the human body occur at the atomic level > X-ray photons exiting the patient interact at the atomic level of the image receptor to create an image.

Transformer

A device used to increase or decrease voltage or amperage, depending on its type

Ampere's Law

A law that tells us that current passing through a wire produces a magnetic field around the wire

Rectification

A process that corrects alternating current so that it flows in on direction only

Electromagnetic induction

A process where putting a conductor (wire) in a constantly changing magnetic field causes electrical current to flow in the wire.

Step-down transformer

A transformer used to decrease voltage and increase amperage in an electrical circuit

Step-up transformer

A transformer used to increase voltage and reduce amperage in an electrical circuit

Hertz (Hz)

A unit of measure to describe the number of AC cycles per second

What does "I" stand for in Ohm's Law?

Amperes or current

Which of the following applies to a radioactive element?

An element that has a spontaneously degenerating nucleus, emitting alpha particles, beta particles, and gamma radiation.

Define molecule.

Any 2 or more atoms bonded together

Resistance

Any property of the conductor that inhibits the flow of electrons (Material, length, diameter, temperature)

The building block of matter is:

Atom

In chemical shorthand, what does the letter "z" stand for ?

Atomic number

What is are isotones?

Atoms that are different, but with the same number of neutrons in their nuclei

The energy which holds the protons and neutrons together in the nucleus and keeps the electrons orbiting around the nucleus instead of floating away is called _______ energy.

Binding

The force that holds the nucleus of the atom together.

Binding energy, or nuclear binding energy

The model and theory of the atom as we know it today is named after which scientist?

Bohr

The model of the atom which we are most familiar with today is:

Bohr atom

Which has the greater amount of charge, the electron or the proton?

Both have equal, but opposite charges

The term "rectification" in regards to electricity refers to_________________.

Causing alternating current to flow in one direction

What are compounds?

Combinations of different elements bonded together

Why is copper an excellent conductor for electrical current?

Copper has a single electron in the outer (valence) ring,

Alternating current (AC)

Current flow that constantly changes direction and power that varies

Direct current (DC)

Current that travels in one direction and delivers continuous power

Which of the following is electrical current that travels in only one direction?

DC

The particle with a negative charge.

Electron

The smallest fundamental particle is the:

Electron

The force that holds electrons in orbit.

Electron binding energy

These define the energy levels at different distances from the nucleus of the atom.

Electron shells

Choose all that are considered to be fundamental particles of atoms from the following choices.

Electron, Proton, &Neutron

Electricity

Electrons moving along a conductor (wire)

Ionization is caused by ____________.

Energy removing an electron from it's orbit in the atom

Electrons, protons and neutrons are known as _________________ particles.

Fundamental

Which of the following is NOT one of the fundamental particles?

Gamma ray

Right Hand Rule

If the right hand is holding a wire with the thumb pointing in the direction of current flow, the fingers will be pointing in the direction of the magnetic field

The term atom comes from the Greek word atomos which means:

Indivisible

The word atom comes from the Greek word atomus, which means:

Indivisible

Which of the following does NOT apply to an element?

Is identified by the number of neutrons in the nucleus (identified by the number of protons in its nucleus)

What iso describes atoms with the same atomic mass number but variations in the number of protons or neutrons?

Isobar

If two atoms have the same number of fundamental particles but with different amount of energy, we have:

Isomers

If we have two atoms with the same number of neutrons and electrons but with different number of protons, we have:

Isotones

1^H and 2^1H are called:

Isotopes

If we have two atoms with the same number of protons and electrons but with different numbers of neutrons, we have:

Isotopes

Two atoms which have the same number of protons but different numbers of neutrons are called:

Isotopes - note the question says protons stay the same

If an atom has the same number of protons and electrons:

It has no electrical charge

The first electron orbital shell in an atom is known as the _______ shell.

K

Electron shell closest to the nucleus:

K shell

Ampere

Measurement for quantity of electrons flowing

Volt

Measures the potential difference/force of the electron flow

If two atoms of hydrogen are bonded together, they make a/an:

Molecule

Are the electrons in the atoms moving or holding still, and if they move are they fast or slow?

Moving by orbiting the atom at a high velocity (very fast)

If the negative charges outnumber the positive charges in the atom, the atom is called a/an:

Negative ion

What 2 words describe an atom with more electrons than protons?

Negative ion

If an atom has an equal number of protons and electrons, what is its charge?

Neutral (no charge)

The particle with mass but no charge.

Neutron

Describe an ionic bond.

One atom gives up an electron (+ charged atom), and another takes on the electron (- charge). Opposing charges attract the two atoms together.

The smallest possible unit of electromagnetic energy is called a (an) _________.

Photon

The charge of the proton is:

Positive

What 2 words describe an atom with more protons than electrons?

Positive ion

The force, or strength of electron flow in an electrical circuit is known as:

Potential difference *Hertz is the unit of measure of the number of cycles per second in AC current. > Resistance is the properties of a conductor that resist current flow. > Electromagnetic induction is the ability to cause electrical current to flow by passing a conductor through a magnetic field. > Current is the number of electrons flowing in electrical current (measured in amperes) > Potential difference is the power, strength, or force of electron flow in a circuit (measured in volts).

Current

Quantity (number) of electrons flowing

Ohm's Law

Relationship between potential difference, resistance, & current. I = V/R

What are elements?

Simplest forms of substances that form atoms. Each element is made of 1 unique type of atom.

Potential difference

The force or strength of the electron flow in the circuit

What does the atomic mass number tell us about the atom?

The number of protons and the number of neutrons in the nucleus

Which of the following best describes the atomic number of an atom?

The number of protons in the atom's nucleus

The atomic number of an atom refers to:

The number of protons in the nucleus

What does the atomic number tell us about the atom?

The number of protons in the nucleus of the atom

When using the formula to determine the maximum number of electrons in a given shell, what number is substituted for the letter n?

The number of the shell. K is numbered 1, L is 2, M is 3, and so on.

An ampere measures __________.

The quantity or number of electrons in the flow of electricity

What is the difference between the following hydrogen atoms? 1^ 1 H and 2^ 1 H

These are isotopes of hydrogen, and the 2nd atom includes a neutron in it's nucleus *Hydrogen does not normally include a neutron in it's nucleus.

Which of the following is true about x-rays?

They have no/neutral charge

(t/f) Most materials that we see in nature are compounds, such as water - not pure elements.

True

Describe a covalent bond.

Two atoms share 1 electron, which orbits both atoms (figure 8 orbit around each nucleus)

What is an alpha particle?

Two protons and two neutrons

An alpha particle is formed from

Two protons and two neutrons bonded together *In certain types of radioactive materials alpha particles are released by the nucleus of the atom in an attempt for the atom to try to become stable. Alpha particles are matter, and are considered to be a type of PARTICULATE radiation (as opposed to x-ray and gamma radiation, which are NOT matter, but instead are electromagnetic radiation - pure energy).

What is an alpha particle?

Two protons bonded to two neutrons

Ohm

Unit of measure for resistance

Producing x-rays requires __________.

Very high voltage and very low current

Which of the following applies to atoms as we know them today?

We use the Bohr model of the atom to describe the location of the fundamental particles The atom is considered to be the basic building block of matter

choose all answers that are TRUE regarding the properties of x-ray.

X-rays are electrically neutral & travel in straight lines

The energy which holds protons and neutrons together in the nucleus of the atom is known as ________________ energy.

binding

If two atoms of copper are bonded together, they form a(n) ____________.

copper molecule *A copper atom is simply one atom. > A copper molecule is 2 or more copper atoms bonded together. Atoms of 2 different elements can also form a molecule. > A compound is always 2 or more different elements bonded together

(t/f) An ionic bond describes atoms which share an electron, where the electron orbits in a figure 8 orbital path around both atoms.

false *This describes a covalent bond.

The name atom comes from the Greek word atomos, which means . . .

indivisible

A proton has ____ unit(s) of positive electrical charge

one

If positive charges outnumber negative charges in in atom, the atom is called a

positive ion