The periodic table presents the elements in the order of:
B) Atomic number
Which of the following physicists had a major part in describing the atom as we know it today?
C) Bohr
Rutherford made what significant contribution to science?
A) Description of the nuclear atom
The binding energy of an electron to a nucleus:
D) Is higher for an L-shell electron than for an M-shell electron
What is the maximum number of electrons permitted in the N-shell?
D) 32
Regarding atomic nomenclature:
A) Atomic mass is the number of protons plus neutrons
Isotopes are:
D) Atoms that have the same atomic
Isomers are atoms that have different:
B) Energy states
Radioactive half-life is the time:
D) Required for radioactivity to reach one half of its original value
The difference between electrons and beta particles is:
D) Electrons originate in shells; beta particles originate from nucleus
Of the following radiations, the MOST penetrating is:
B) X-ray and gamma
Which of the following types of radiation are emitted from outside of the nucleus?
D) X-rays
X-ray wavelength is:
D) Inversely proportional to frequency
A single unit of electromagnetic radiation is also called a/an:
C) Photon
The frequency of electromagnetic radiation is:
A) Measured in Hertz
The frequency of a sine wave is:
D) The number of crests that pass per second
According to latest research, the principal difference between x-rays and gamma rays is their:
D) Origin
When white light is refracted through a prism, the following colors are emitted. Which has the longest wavelength?
C) Red
For any electromagnetic radiation:
C) An increase in frequency results in an increase in energy
Electromagnetic radiation:
A) Exists only if its velocity is 3 x 108 m/s
Which of the following characteristics is the same for both ultraviolet radiation and microwaves:
C) Velocity
Which of the following MOST closely represents the term ATTENUATION?
C) Light transmitted through frosted glass
The energy of an x-ray photon is directly proportional to its:
C) Frequency
The equivalence of mass and energy is described by:
B) Einstein’s theory
In the equation E = hf, the h:
A) Stands for Planck’s constant
What are the four types of atoms?
Greek
Dalton
Thompsson
Bohr
What are the characteristics of a Greek atom?
Scientist thought all matter was composed of four substances:
Earth
Water
Air
Fire
Atom means indivisible
Could organize these substances by varying essences (wet,dry, hot, cold)
Describe John Dalton's work
-Elements classified by atomic mass
-Hook and eye atom
-Elements composed of identical atoms react in the same way, look alike, and constructed alike
-Hook and eye theory
Who is Dmitri Mendeleev?
-Arranged atoms in order of increasing mass
-Designed the first periodic table
-Modern periodic table today arranges elements that react the same chemically
Describe Thompson's work
-Plum pudding theory
-Electrons are negative (plums)
-Pudding is positive
Who is Earnest Rutherford?
-Disproved plumb pudding
-Nuclear theory
-Placed the nucleus in the center
-Nucleus had a positive charge
Who is Niels Bohr?
-Atom is a mini solar system
-Bohr – credit for what atom looks like, + charged nucleus surrounded by negatively charged electrons in orbits
-Normal or neutral atoms have the same number of protons and electrons.
What is a necleon?
protons and neutrons
Electrons have a mass of ____________
9.1 x 10-31 kg
Electron binding energies (Eb) or energy levels are represented by ________
shells
The ________ the shell of electrons is to the nucleus, the stronger the Eb
closer
# protons = # of ________ (in orbits) SO
electrons
# ________ determines chemical behavior
protons
# protons determines ___________ __________
chemical element
n# of shells = _________
period
n# of e- in outermost shell =________
group
NO outer shell can contain more than eight e- because there are _________ groups
8
The number of ______ in the outermost shell of an atom is equal to its _______
electrons, group
Shells are identified by letters of the alphabet, the innermost being the (__) shell.
K
The maximum number of electrons that can exist in an electron shell is calculated with the formula ________
2n2
____________ force keeps electron from
flying away “center-seeking”
centripetal
Velocity of e is ____________ force “flying out from the center”
centrifugal
Atomic number is the number of _______
protons
Atomic Mass is the total number of ______ and _________
protons, neutrons
Isotopes are atoms that have the same atomic number but different atomic mass numbers. So isotopes have the same number of _________ different number of neutrons
protons
Isobars are atomic nuclei that have the same atomic mass number but different atomic numbers
-Different # of ____________
-Different # of ____________
-Same # of __________
protons
neutrons
nucleons
_______ are atoms that have the same number of neutrons but different numbers of protons
-Different atomic numbers
-Different mass numbers
-Constant A-Z (neutrons)
isotones
Isomers have the same atomic number and the same mass number
-Identical atoms but exist in different _________ __________ because of differences in nucleon arrangement
energy states
Some atoms have an abnormally excited stated caused by an unstable ________. In order to become stable, the atom emits particles and energy in attempt to transform itself into another atom, called _________. This process is called radioactive decay or disintegration.The atom is call a ________ because it is undergoing this disintegration
nucleus, radioactivity, radionuclide
Radioisotopes decay to stability by two methods. One is through _______ emission and the other is through _________ emission.
alpha, beta
_______ emission – happens more often then alpha emission
-Electron particle is ejected from atom
-Increases the atomic number by 1
-Neutron converts to a proton
beta
_______ emission - more violent -has 2 protons & 2 neutrons bound together
-Loses 2 units of positive charge
-Loses 4 units of mass
alpha
_______ rays are given off during alpha and beta emission
gamma
The _______ (T½) of a radioisotope is the amount of time required for the quantity of radioactivity to be reduced to half of its original value.
half-life
Formula for Half Life
y = 100(½)x
•x represents the interval between half lives
•y = the current amount
What are the types of Ionizing Radiation
-Particulate Radiation
-Electromagnetic Radiation
The only difference between x-rays and gamma rays is their _________.
origin
X-rays are produced outside the nucleus in the ________ ______
electron shell
Gamma rays are emitted from the _______ of a radioisotope – associated with beta and alpha emission
nucleus
___________ ____________ is a form of energy that is reflected or emitted from objects in the form of electrical and magnetic waves that can travel through space
electromagnetic energy
Properties of photons
-frequency
-wavelength
-velocity
-amplitude
Greeks called an atom of light a ___________
photon
Small bundle of energy,_____________, traveling through space at the speed of light
quantum
______ _________ ________ showed that light has electric and magnetic properties, hence electromagnetic radiation
James Clerk Maxwell
Electric field governs __________________
electrostatic charge
Magnetic field governs ___________________
magnetic poles
Photons travel in a ________ ________
sine wave
Sine waves are variations of __________ over time
amplitude
______________ is one half the range from crest to valley over which the sine wave varies
amplitude
_______ is the number of wavelengths that pass a point of observation
Frequency
What is measured in hertz (Hz)1 Hz = 1 cycle/second?
frequency
___________ (λ) is the distance from one crest to another, from one valley to another, or from any point on the sine wave to the next corresponding point
wavelength
At a given velocity (c) wavelength and frequency are _________ proportional
inversely
What is the formula for velocity?
velocity = Frequency x wavelength
v = fλ
___________________ consists of photons with wavelengths longer than those of visible light but shorter than those of microwaves
infared light
_________________ is located between visible light and ionizing radiation
ultraviolet light
VERY long wavelength and low energy is _____________ radiation
radio
Visible light act more like a ____________
wave
X-ray photons act more like a _______________
particle
What is absorption?
- transfer of energy from an electromagnetic field to matter
What is attenuation?
- the reduction in intensity resulting from scattering and absorption
______________ allows light to be transmitted almost unaltered (glass)
transparent
Light transmitted but scattered and reduced in intensity through a material called ___________________
tanslucent
Glass painted black is _______________ and no light can pass through, any incident light is absorbed
opaque
Structures that absorb x-rays are described as __________, such as bone.
radiopaque
Structures that attenuate x-rays are called ___________, such as soft-tissue.
radiolucent
Radiation intensity is _______ related to the square of the distance from the source
inversely
What is the inverse square law?
•If you ½ distance, you quadruple exposure
•If you double your distance, you ¼ exposure
•If you 1/3 your distance, your exposure will increase by 9 times
•If you triple your distance, you get 1/9 exposure
What's the formula to the inverse square law?
I1 D22
=
I2 D12
Who is Max Planck?
•Max Planck (German physicist)
•Nobel Price in 1918
•Mathematical and physical theories helped our understanding of electromagnetic radiation into a uniform model
•Planck’s quantum theory
–Exist at speed of light or they don’t exist
What is Planck’s quantum theory?
–Exist at speed of light or not at all
–Photon energy is directly proportional to photon frequency
–This constant proportionality is Planck’s constant