Subshells and energy levels Flashcards
What are shells made of?
Shells (principle quantum shells) are made of sub shells and they are made of orbitals
What is the principle quantum number?
The number of shells
What does a higher shell number mean?
The higher the energy of electrons in each shell
What are the labels of sub shells and their energy levels?
s,p,d and f and they increase s<p<d<f
What is shell 1?
It is only one sub shell, which is an s sub shell, so it is labelled the 1s sub shell
What is shell 2?
It contains 1 s subshell and 1 p subshell, labelled the 2s subshell and the 2p subshell
What is shell 3?
Contains 1 s subshell, 1 p subshell and 1 d subshell, labelled the 3s subshell, 3p subshell and 3d subshell
What are s subshells
They are made of 1 orbital and can hold a maximum of 2 electrons
What is the p subshell?
It is made up of 3 orbitals and can hold a maximum of 6 electrons
What is the d subshell?
It is made up of 5 orbitals and can hold a maximum of 10 electrons
Why are orbitals degenerate?
In any subshell, all orbitals have the same energy level
What are orbitals?
Regions which can hold up to a pair of electrons with opposite spins
How many electrons have an orbital hold?
A maximum of 2 each
What are the different types of orbital?
s, p, d and f
What is the shape of an s orbital?
Spherical ( O )
What is the shape of a p orbital?
Dumbbell ( OO )
What is the maximum number of electrons in the first shell?
2
What is the maximum number of shells in the second shell?
8
What is the maximum number of shells in the third shell?
18
How are electrons represented when drawn?
As arrows and if there are 2, one arrow is up and one is down
What is Hund’s rule?
When filling a subshell, a single electron must be present in every orbital before a second one is added
How is the 4s subshell filled?
It is filled first when drawing a diagram but when it is written out, all the ‘3’ subshells are kept together
What is the electron configuration of copper?
1s2 2s2 2p6 3s2 3p6 3d10 4s1
What is the electronic configuration of chromium?
1s2 2s2 2p6 3s2 3p6 3d5 4s1
How can electron configurations be shortened?
By using the symbol of the noble gas from the previous period and additional configuration, e.g, Zn = [Ar] 3d10 4s2
What is the s block of elements?
Group 1 & 2 and helium
What is the p block of elements?
Groups 3 (excluding transition metals) to 8 (excluding helium)
What is the d block of elements?
The transition metals
What is the f block of elements?
The lanthanides and actinides
Why are elements sorted into blocks?
It is based of which subshell their outmost electron is in
Why is there a decrease in first ionisation energy from group 2 to group 3?
Because less energy is required to remove electrons from the p subshell as it is a higher energy subshell so it is easier to remove the outer electron so first ionisation energy is lower
Why is there a decrease in first ionisation energy from group 5 to 6?
Because in group 6, there is a pair of electrons in the first orbital so they repel eachother. This means less energy is required to remove electrons from paired subshells due to repulsion so less energy is required to remove the outer electron, the first ionisation energy is lower
