Waves and Photons
What is the relationship between wavelength, frequency, and the speed of light?
C = λf
Who proposed that electrons move around the nucleus in specific energy levels?
Niels Bohr
What does the principal quantum number (n) represent?
Energy level or shell
Write the shorthand electron configuration for sodium (Na).
[Ne]3s¹
What happens to atomic radius as you move left to right across a period?
It decreases
If a radio wave has a frequency of 1.5×10⁶ Hz, what is its wavelength?
200m
Calculate the wavelength of light emitted when an electron in a hydrogen atom falls from n=2 to n=1
122 nm
For n=3, what are the possible values of l?
0, 1, 2
Write the shorthand configuration for bromine (Br).
[Ar]4s²3d¹⁰4p⁵
Arrange Na, Al, and Mg in order of increasing ionization energy.
Na < Al < Mg
Light has a wavelength of 400 nm. What is its frequency?
7.5×10¹⁴ Hz
Calculate the wavelength for the n=3 → n=2 transition in hydrogen.
656 nm
For l=2, what are the possible ml values?
-2, -1, 0, +1, +2
What is the configuration of Mg²⁺?
[Ne]
Which has the larger radius: Ca or Ca²⁺?
Ca
What type of electromagnetic radiation has the longest wavelength?
Radio waves
What is the ionization energy (in J) of a hydrogen atom from the n=1 level?
2.18×10⁻¹⁸ J
Identify if this set is valid: (n=3, l=2, ml=3, ms=½).
Invalid (ml can’t be +3)
What is the configuration of Cu?
[Ar]4s¹3d¹⁰
Which bond is more polar: C–O or N–Cl?
C–O
A laser emits light at 633 nm. How many photons are emitted if it releases 2.0×10⁻³ J of energy?
≈6.4×10¹⁵ photons
When an electron in a hydrogen atom absorbs energy, what happens to its energy level?
a) It moves to a lower level
b) It moves to a higher level
c) It stays the same
d) It becomes neutral
b) It moves to a higher level
What is the maximum number of electrons that can occupy the n=4 level?
32 electrons
Which atom has the configuration [Kr]5s²4d⁸?
Palladium (Pd)
Arrange F⁻, Na⁺, and N³⁻ in order of increasing ionic radius.
Na⁺ < F⁻ < N³⁻