Atomic Structure - Electron Shells And Orbitals Flashcards
What do we know about electron shells?
3
Electrons orbit the central nucleus
They orbit in shells
The first 4 shells can hold different numbers of electrons
How many electrons can each shell hold?
2n*2
How many electrons are in the 1st shell?
2
How many electrons are in the 2nd shell?
8
How many electrons are in the 3rd shell?
18
How many electrons are in the 4th shell?
32
How do you work out the shells for:
1st shell
2nd shell
3rd shell
4th shell
1 = 2(1)*2
2 = 2(2)*2
3 = 2(3)*2
4 = 2(4)*2
2n*2 electrons per shell
What does n represent?
Principal quantum number
Do electrons orbit the nucleus?
Don’t exactly orbit nucleus
If electrons did orbit the nucleus what would we be able to do?
Plot the path of their movement
Calculate where an electron is at one instant and where it is an instant later
What does the Heisenberg Uncertainty Principle state?
It is impossible to certainly say where an electron is and where it will be going
What are electron shells made up of?
Atomic orbitals
What are orbitals?
A region in space where electrons MAY be found
How many orbitals is each shell composed of?
1 or more orbitals
How many pairs of electrons can an orbital hold?
1 pair of electrons
What are the 4 types of orbitals?
s - Sharp
p - Principal
d - Diffuse
f - Fundamental
What do the orbital names refer to?
The lines produced on spectra by these orbitals
What shape are s orbitals?
Spherical shape
s orbitals
How many orbitals does each shell from n=1 upwards contain?
Every shell contains 1 s orbital
What shape are p orbitals?
3D dumbbell shape
What are the 3 p orbitals?
Px
Py
Pz
(Depends on the axis it’s on)
p orbitals
How many orbitals does each shell from n=2 upwards contain?
3p orbitals
One on each of the x, y, z
How many electrons can each p orbital hold?
2 electrons
3 x 2 = 6 electrons in total
d orbitals
How many orbitals does each shell from n=3 upwards contain?
5 d orbitals
5 x 2 = 10 electrons in total
Which orbitals can be found in n=1?
s orbitals
Which orbitals can be found in n=2?
s orbitals
p orbitals
Which orbitals can be found in n=3?
s orbitals
p orbitals
d orbitals
How many electrons are in n=1?
2
How many electrons are in n=2?
8
s orbital = 2
p orbital = 6 (2x3)
How many electrons are in n=3?
18
s orbital = 2
p orbital = 6 (2x3)
d orbital = 10 (2x5)
What are sub shells?
Orbitals that are of the same energy level are grouped together
What is each sub-shell composed of?
Only one type of atomic orbital
n=1
Orbital - s
Electrons - 2
What is the sub-shell?
1s
n=2
Orbitals - s p p p
Electrons - 2 2 2 2
What are the sub-shells?
2s
2p
n=3
Orbitals - s p p p d d d d d
Electrons - 2 2 2 2 2 2 2 2 2
What are the sub-shells?
3s
3p
3d