Atomic mass

The number or protons plus number of neutrons in an atom

Atomic number (z)

The number of protons in the nucleus of an atom

Electron binding energy (Eb)

The amount of energy needed to remove the electron from the atom or the strength or force of attachment of an electron to an atom (how tightly they are bound)

Element

Substance which cannot be reduced further without changing its chemical properties

Isotopes

Atoms with the same number of protons in the nucleus but a different number of neutrons

Octet rule 

state that the number of electrons in the outermost shell never exceeds 8 electrons

Radioactive decay

Process by which the nucleus spontaneously emits particles and energy and transforms itself into another atom to reach stability

Radioisotopes 

Radioactive atoms that have the same number of protons 

Atom

the smallest particle of an element that cannot be broken down by ordinary chemical means 

The Bohr Atom

In 1913 a Danish physicist Niels Bohr first described the atom as a “miniature solar system”

Negatively charged electrons revolve about a positively charged nucleus in prescribed orbits or energy levels

Newer model called quantum chromodynamic (QCD) String theory

3 fundamental parts of an atom, charge, location, mass, charge 

protons positive nucleus 1.673×10^27 0 AMU 0

neutrons neutral nucleus 1.675×10^27 0 AMU +1

electrons negative shells (orbits) 9.1×10^31 0 AMU -1

elements are often indicated by an alphabetical abbreviation called 

chemical symbol 

in a neutral atom the number of electrons equals the number of 

protons

elements arranged in what based on the periodic table

increasing atomic mass 

the number of protons ultimately determines the

chemically behavior of an atom

formula to calculate the number of electrons per shell

2n²

what is the shell occupancy of K, L, M

2,8,18

Valence electron

the number of electrons in an atoms outermost shell

determines its ability to bind with other atoms

how it is transferred to or shared with other atoms (donated, accepted, shared)

centripetal force

center seeking (opposites attract) keep things from flying into space

centrifugal force 

flying out from the center force. electron velocity around orbit of nucleus prevents it from collapsing into nucleus (gravitron)

ionization

the removal or ejection of an orbital electron from the atom

tungsten approximate binding energy 

69.5

As the atomic number of an element increases, the K shell binding of the element 

Increases 

within the same atom binding energy… as you move further from the nucleus

decreases 

Which of the following shells have the greatest binding energy 

K shell 

Which of the following shells possess the greatest total energy

p shell

All elements in the same group (column) react chemically in a

similar fashion and have similar physical properties

it takes _ eV or higher to ionize tissue within the human body

34

attenuation

reduction in radiation intensity that result from both absorption and scattering

The reduction in the number of x-ray photons in the beam, and subsequently loss of energy, as the beam passes through matter

isotope

same number of protons

isobar

same number of proton and neutrons (atomic mass)

isotone

same number of neutrons

isomer

all the same

2 types of chemical bonds

covalent-sharing of pairs of electrons 

ionic-”attraction between two oppositely charged ions”

radioactivity

defined as the rate of decay or disintegration of radioactive material  

expressed in curie or becquerel 

radioactive half life

the time required for a quantity of radioactivity to be reduced to one half its original value 

constant rate 

never quiet reaches 0 

types of ionizing radiation

particulate and electromagnetic

particulate

alpha, beta

em

x-rays, gamma rays, uv light (photons- no mass, neutral, travel at the speed of light, energy disturbance in space)

origin of gamma rays and x rays

emitted from the nucleus of a radioisotope

produced outside the nucleus in the electron shell  

what properties of x-rays make them particular useful for medical imaging 

unlimited range, low ionization rate

Barium 

Ba, Z=56, A=137

Tungsten

W, Z=74, A=184

molybdenum

Mo, Z=42, A=96

Lead

Pb, Z=82, A=207