Unit 4 Review
Name _________Key________________ Date ______________ Period ______
I. Fill in the blanks with the most appropriate term.
In Bohr’s model of the atom, electrons are in certain ___energy________ levels, with the levels closest
to the nucleus of ___lowest____ energy than those farther from the nucleus. In the
__ground_________ state of an atom, the electrons are in the lowest __energy______ level possible.
When an atom absorbs energy it is said to be in an ____excited_______ state, which is unstable. The
atom will soon __lose______ the same amount of energy it absorbed and it can be seen as ___visible_
__light_____. This is the __atomic_ ___emission______ spectrum and is unique to each element.
The modern view of light is that it has a ____dual______ nature. In other words, light may behave as a
stream of particles called ____photons_____ or it may behave as a _____wave______.
In the wave view of light, the wave equation is often used to determine a wave’s frequency or
wavelength. The ___wavelength_______ is the distance between corresponding points on adjacent
waves while ____frequency__________ is the number of waves passing a given point in a given time.
The wave equation is ____c=λf_______________.
II. Use the wave equation to solve the following:
1. What is the frequency of light with a wavelength of 1.87 X 10-14 m?
f= 3.00 x 108 m/s
1.87 x 10-14 m
2. What is the wavelength of light with a frequency of 5.6 X 1014 Hz?
λ = 3.00 x 108 m/s
5.6 x 1014 s-1
III. Short answer:
1. According to Planck’s equation E=hf, what is the relationship between frequency and energy of light?
Increased frequency = increased energy
2. According to the wave equation, what is the relationship between frequency and wavelength of light?
Greater frequency = shorter wavelength
IV. Electron distribution:
1. How many energy levels are there? ___7_____ What do they correspond to? _____periods______
2. There are four types of orbitals: they are ____s,p,d,f____________
__s_ is sphere shaped and there is only one kind - it can hold _2___ electrons total
p is dumbbell shaped and there are ___3___ kinds – they can hold a total of ___6__ electrons
_d_ is a double dumbbell with a donut and there are __5____ kinds – they can hold _10_ electrons total
__f_ is too complex to describe or draw and there are __7_ kinds – they can hold __14_ electrons total
Rule that states:
Electrons must fill lowest energy levels first
________Aufbau Principle_____________
Each orbital can hold only two electrons ____Pauli Exclusion______________________
Two electrons in the same orbital will have opposite spin ___Hund’s rule_______________
Can’t know the exact location/velocity of an electron __Heinsenberg Uncertainty ______________
Orbitals of equal energy fill singly before doubling ____Hund’s rule______________________
For the following elements, write the complete electron configuration, the noble gas configuration, and
the orbital diagram.
Si
Ni
C
1s22s22p63s23p2
1s22s22p63s23p64s23d8
1s22s22p2
Periodic Trends:
Atomic radius _____decreases____ across a period and ____increases_______ down a group.
Ionization energy ___increases____ across a period and ____decreases______ down a group.
Electronegtivity_____increases ___ across a period and _____decreases_____ down a group.
Shielding effect_____constant____ across a period and _____increases _____ down a group.