Electronic Structure 2.2.1 Flashcards
Shells are made up of what
Sub-shells
What are subshells made up of
Atomic orbitals
Name the subshells
S, P, D, F
Name the orbitals
SPDF
What is S subshells made up of
1 single s orbital
What is P subshell made up of
3 p orbitals
px
py
pz
What is D subshell made up of
5 d orbitals
What is f subshell made up of
7 f orbitals
What is the term shells commonly known as
Principle energy level or principle quantum number
What is principle quantum number n
A number representing the relative overall energy of each orbital. The sets of orbitals with the same n value are referred to as electron shells or energy levels
Scientists have given each shell a number n- this is referred to as the principle quantum number e.g. first shell has PQN of 1
seconds shell has pqn of 2
third shell has pqn of 3
and so on
-it’s used in the equation 2n squared to find maximum number of electrons in each shell
What does an increase to PQN represent
Increase to principle quantum number represents an increase in relative overall energy as we move further from the nucleus
n=2 is further from nucleus than n=1 so it’s got more relative energy
As we mover further from the nucleus the relative energy increases due to decrease interaction between nucleus and electrons orbiting it so the higher the pqn the further the electrons from the nucleus the higher the relative overall energy
Define sub-shell
A group of the same type of atomic orbitals within a shell
Define atomic orbitals
A region around the nucleus that can hold up to 2 electrons with opposite spins
What is the shape of an s orbital
Sphere
What is the shape of a p orbital
Dumb bell
How do you represent the opposite spins in an orbital
in the box draw two arrows one facing upwards one facing downwards
An s sub-shell can hold how many orbitals and therefore how many electrons
S sub-shell= 1 orbital so it can hold a maximum of 2 electrons
An p sub-shell can hold how many orbitals and therefore how many electrons
P sub-shell= 3 orbitals so it can hold a maximum of 6 electrons
An d sub-shell can hold how many orbitals and therefore how many electrons
D subshell= 5 orbitals, each orbital can hold 2 electrons so it can hold a maximum of 10 electrons
Shell 1 contains what sub-shells
1s sub-shell
Shell 2 contains what sub-shells
2s, 2p sub-shells
Shell 3 contains what sub-shells
3s, 3p, and 3d subshells
Shell 4 contains what sub-shells
4s, 4p, 4d, 4f sub-shells
What is the AufBau principle
Electrons fill the sub-shells with order of increasing energy. The order is 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p for the elements hydrogen to krypton
What is Hund’s rule
Within a sub-shell the orbitals are first occupied singly by unpaired electrons. The electrons only pair up when there are no empty orbitals left in the sub-shell
BUSSESS!!!!!!!!!!!!!
In an orbital the 2 electrons must have…
Opposite spins
What is meant by ‘opposite spins’ when referring to the two electrons in an orbital
one electron spins clockwise and one anticlockwise
How do you work out the maximum number of electrons in a shell or energy level
By using the formula 2n2
n = number of the shell (energy level)
What does the period number tell you about electronic structure of an atom
Numbers of the periods – tells you which shell is being filled
How do electrons know which orbital to go into first e.g. 3d or 4s
- Electrons enter the lowest energy orbital available (4s is lower energy than 3d when empty)
How do you work out which block an element belongs to
Look at the number of the period + the block to work out which sub shell the highest energy electrons are in on the atom
Learn the blocks on the periodic table s, p, d, f
It is in the Gap task: Atomic and Electron Structure, Isotopes and Formulae test booklet
Go to Question 10 there is a grid on that page and some questions on the bottom for practice
What happens to the energy of the sub-shells as we move further away from the nucleus
As we move further away from the nucleus the energy of the sub-shells increases
Why do we put electrons into individual orbitals before filling them up as pairs
As the orbitals have the same energy, we put electrons in individually because the electrons in the same orbital repel
What do we fill up first 4s or 3d
Fill 4s before 3d because it has lower energy than 3d when its empty
When 4s contains electrons as it fills up before 3d what happens to the electrons when they have to leave a sub-shell
When 4s contains electrons it is higher in energy than 3d, and electrons leave from 4s before 3d
Write out the full Electron configuration of Silicon and the Short hand version
Silicon = 14 e-
Full electron configuration :
1s2 2s2 2p6 3s2 3p2
- Shorthand electron configuration [Ne] 3s2 3p2
What do we not write when writing the electron configuration of an element e.g. Silicon
The GCSE version of 2, 8, 4
What 2 elements do not have expected electron structure
Chromium and Copper
Why do Cu and Cr not have expected electron Structure
Cu and Cr do not have the expected electron structure because the atom is more stable with half full or full sub shells
What is the Electron Configuration for Chromium
Cr = 1s2 2s2 2p6 3s2 3p6 4s1 3d5
What is the electron Configuration of Copper
Cu = 1s2 2s2 2p6 3s2 3p6 4s1 3d10
What happens when an anion is formed
writing electron configuration for ions
More electrons are added when a negative ion (anion) is formed-
What happens when a cation is formed
The highest energy electrons are lost when a positive ion (cation) is formed.
What is affected within the electronic structure of the atom when it becomes an ion
The highest energy sub-shell
if an atom becomes a cation then it will loose electrons from the highest energy sub-shell and if an atom becomes an anion then it will gain electrons and expand on the highest energy sub-shell
In an s orbital the greater the shell number n the greater the…
Radius of the s orbital
The p orbitals are…
At right angles to eachother
In a p orbital the greater the shell number the…
Further away the p orbital is from the nucleus
The highest energy level in the third shell overlaps with the lowest energy level of the fourth shell. True or false
True, 4s has slightly less energy than 3d when empty so is filled up before the 3d
Chloride Ion is isoelectronic with what
An Argon Atom
