Scientists
This scientist proposed that electrons travel in specific orbits around the nucleus.
Niels Bohr!
Bohr’s model introduced the idea of certain energy levels for electrons in an atom.
What does the quantum mechanical model describe?
The behavior of electrons as waves in orbitals!
The model explains that electrons behave like waves and exist in regions called orbitals.
Which quantum number represents the main energy level?
Principal quantum number (n)!
This number determines the energy level of an electron.
Which orbital is spherical?
s-orbital!
What is the electron configuration of hydrogen?
1s2
Hydrogen has one electron, which occupies the 1s orbital.
The scientist who discovered the nucleus by shooting alpha particles at gold foil.
Rutherford!
Rutherford’s gold foil experiment showed that most of the atom is empty space. (He did not expect this!)
What does the uncertainty principle say?
You can’t know both the position and momentum of a particle at the same time!
Heisenberg showed that measuring one property either position or momentum will affect the other.
Which quantum number shows the shape of the orbital?
Angular momentum number (L)!
This number defines the shape of orbitals.
Which orbital is dumbell shaped?
p-orbital!
Dumbbell shape with two lobes.
What is the short hand configuration of sodium?
[Ne]3s1
Sodium has 11 electrons, the first 10 match neon (Ne), and one is in 3s.
This scientist is known for proposing the first modern atomic theory, stating that all matter is made of atoms.
Dalton!
Dalton’s atomic theory explained that atoms combine in specific ratios to form compounds. We know this as the law of multiple/definite proportions!
Which experiment showed electrons behaving like waves?
Double-Slit experiment!
Electrons passing through two little slits create a wave-like pattern (wave-particle duality).
What are the possible values of the magnetic quantum number (mL) for a p-orbital?
-1, 0, +1!
mL can take values from -L to +L
Which orbital has five orientations and appears at n=3?
d-orbital!
The d-orbitals have five orientations and first appear in the 3rd energy level.
What rule says electrons fill orbitals one at a time before pairing?
Hunds rule!
Electrons occupy orbitals of the same energy level before pairing.
What is Heisenbergs Uncertainty Principle, and who came up with it?
Schrodinger found that due to wave nature of matter, it is impossible to predict both the position AND momentum of an electron with certainty!
What principle says electrons fill the lowest energy orbitals first?
Aufbau Principle!
Electrons fill lower-energy orbitals before higher ones (1s fills before 2s).
Which quantum number shows how electrons spin?
Spin Quantum Number (ms)!
Electron spins can be represented as either - 1/2, or + 1/2
What is the maximum number of electrons in one orbital?
2!
An orbital can hold 2 electrons, one spinning up and the other spinning down. (+1/2, -1/2)
What is the electron configuration of oxygen?
1s22s22p4
Oxygen's 8 electrons fill the 1s, 2s and 4 spaces in 2p.
What is a limitation to the 2 laws that Dalton proposed?
Law of multiple/definite proportions could not explain why atoms of elements combine in the ratio they do!
What idea explains that electrons can behave like waves and particles?
Wave-Particle Duality!
It shows that electrons have both wave and particle behaviors
How many orbitals are in the 3rd energy level?
9!
There are 1s, 3p, and 5d orbitals, totalling 9 in the third energy level.
How many f-orbitals are there?
7!
There are 7 f-orbitals with different orientations.
How many electrons are in a 3d5 configuration?
5!
A 3d5 configuration means 5 electrons occupy the d orbital.