This philosopher is considered to be the earliest recorded reference to atomic theory.
Democritus
the atom is composed of these three particles
protons, neutrons, electrons
the spontaneous emission of rays or particles from the nucleus of an atom.
nuclear decay
Isotopes are considered to be the SAME element.
True
The atom has energy levels that are often called ___.
shells
Speed of light?
3x108 m/s
His opinion about the composition of matter in the universe dominated the world for ~2 millennia
Aristotle
These subatomic particles are positively charged
protons
This radiation requires at least 4 meters of lead to block.
gamma radiation
Mass number represents...
#protons + #neutrons
This principle states that only two electrons can occupy an orbital
Pauli exclusion principle
6.626 x 10-34 J*s
Plank's constant (h)
William Crookes famously discovered "negatively charged particles" using what instrument?
cathode ray tube
How is mass distributed in an atom?
dense core/nucleus/ mostly empty space
Which type of radioactive decay does not produce a different element?
gamma decay
In isotope notation, the superscript represents __.
mass number
Electrons must fill lowest energy states first
Aufbau principle
nanometer (nm)
This experiment helped determine the mass and charge of an electron.
Oil drop experiment
Atoms that possess the the same number of protons, but a different number of neutrons.
isotopes
The process of emitting a He2+ ion
alpha decay
Quantifies the occurrence of a particular isotope in nature.
relative/natural abundance
Orbitals of the same energy must be singly occupied by electrons before being doubly occupied.
Hund's rule
Waves can be described purely as waves using what equation?
c = wavelength(frequency)
This experiment proved that an atom is mostly empty space with dense core called nucleus.
Gold foil experiment
If an atom loses or gains electrons, then it is referred to as an ___.
ion
Deflected toward a positively charged plate.
beta particle
what does the number 14 represent in "nitrogen-14"?
mass number
electron configuration of He2+
none
The energy of a photon can be expressed as...
E = hv =hc/lambda
What particle was used by Rutherford to investigate the structure of gold atoms.
alpha particle
The heaviest subatomic particle
neutron
What type of decay is this?

Beta decay

What is the average mass of of an element that has isotope A (70 amu; 50% abundance) and isotope B (71 amu; 50% abundance)?
70.5 amu
Unabbreviated electron configuration of carbon (C)
1s22s22p2
Calculate the frequency of a photon that has 6.6 x 10-34 J of energy. You can round.
1 s-1 (Hz)
Dalton revived the _ _.
atomic theory
Atomic number represents what?
number of protons
Nuclei of atoms can be forced apart in a process called
nuclear fission
What determines the identity of an element?
#protons
How many orbitals are in the d-sublevel?
5 orbitals
What is the mass of a photon?
massless
Dalton's theory was 100% correct. T/F
False
Negatively charged particles
electrons
The wavelength of __ are so small that they can blast through DNA.
gamma rays
This is neutral in its charge.
neutron
How many electrons can fit inside of the third shell?
18 electrons
Which travels faster? radio waves or gamma waves?
Neither...
c = 3.0 x 108 m/s for all electromagnetic radiation.
Proposed the first quantum model of the atom.
Niels Bohr
What element has an atomic number of 7
nitrogen
Which radiation is the most harmful?
gamma radiation
Too many extra neutrons will cause an atom to become __.
unstable
How many valence electrons in the valence shell of krypton (Kr)?
8 (full valence shell = noble gas)
Which electromagnetic radiation can travel the furthest distance?
radio waves
Concluded that energy from light was quantized into little energy packets called photons.
Planck
How many electrons does carbon have?
6 electrons
Thin sheet of paper can block this
alpha particle
How many neutrons are in an element with 6 protons and a mass number of 14
8 neutrons
What sublevels are in the 3rd shell?
3s, 3p, 3d
The types of light exist on a ___.
(electromagnetic) spectrum
Famously concluded that it is impossible to know both the position and motion of an electron.
Heisenberg
An electron absorbs a photon and is promoted to a higher shell/energy level.
excitation
Not effect by electric field from charged plates
gamma rays
An element has isotopes A, B, C with masses 12, 13, and 14 amu, respectively. The average atomic mass is 12.30 amu. Which isotope has the higher abundance?
isotope A
Abbreviated electron configuration of chloride (Cl-)
[Ar]
With increasing wavelengths, the frequency of light ___.
decreases
His wave equations were used to determine how electrons are arranged around the nucleus.
Schrödinger
Electrons occupy 3 dimensional volumes of space surrounding the nucleus.
Orbitals
Whats happens to the nucleus of an atom after beta decay?
neutron converted to proton 
Element X has average atomic mass of 100 amu
isotope X1 (101.5 amu; 30% abundance)
isotope X2 (99.0 amu; ----------)
What is the abundance of isotope B? You can round.
70%
The abbreviated electron configuration of Caesium (Cs)?
[Xe]6s
Particles (e.g. protons and electrons) can also behave like waves. What equation describes this phenomena?
de Broglie wave-particle equation
In the early 20th century, lithium (Li) was utilized as a mood-stabilizer in what soft drink?
7-up