Ionisation

Question 1

First ionisation energy

Answer 1

The energy required to remove 1 electron from every atom in one mole of gaseous atoms to form one mole of 1+ ions

Question 2

Second ionisation energy

Answer 2

Energy required to remove 1 electron from every ion in one mole of gaseous 1+ ions to form one mole of gaseous 2+ ions

Question 3

Successive ionisation energies

Answer 3

What occurs when more electrons are removed from an atom, requires more energy each time because of increased electrostatic attraction between the electron and nucleus also less shielding

Question 4

When writing ionisation equation

Answer 4

(g) state symbol
Only 1 electron is removed
Charge increases
The number of successive ionisation energies is the same as the charge formed on positive ion

Question 5

How does the electron in ionisation energy get removed?

Answer 5

The energy supplied is used to overcome the electrostatic attraction between negative electron and positive nucleus
This energy value is the same for all electrons in a given atom
But electrons are at different energy levels in an atom due to shells and shielding so need different amounts of energy to get to this point so different IE

Question 6

What does the ionisation energy depend upon?

Answer 6

How strong the electrostatic attraction between the nucleus and electron is

Question 7

What happens if the electrostatic attraction between the ionising electron and nucleus is strong?

Answer 7

Then the ionisation energy will be strong because more energy is required to overcome this attraction

Question 8

What factors affect the electrostatic attraction thus the ionisation energy?

Answer 8

Shielding
Number of protons
Size of atom
SNS
(Spin sometimes of the electron)

Question 9

Shielding

Answer 9

A decrease in the nuclear charge experienced by an outer shell electron caused by electron-electron repulsionbetween the outer shell electron and electrons from adjacent quantum shells

Question 10

How does shielding have an effect on ionisation energy?

Answer 10

With increased number of electrons there is more repulsion between them
So increases the energy between them causing a decrease in energy to remove the electron

Question 11

Nuclear charge

Answer 11

The positive charge produced by protons on the nucleus
Causes electrostatic attraction between electrons

Question 12

How does nuclear charge have an effect on ionisation energy?

Answer 12

The greater number of protons means greater nuclear charge
So greater electrostatic attraction between the electron and nucleus
So ionisation energy is greater

Question 13

Size of atom/ distance electron from nucleus

Answer 13

When there are more internal shells the electron is further away
And electrostatic attraction decreases sharper if it’s further away

Question 14

How does distance of atom/ distance electron is from nucleus affect ionisation energy?

Answer 14

If there are less internal shells between the electron and nucleus
Then electrostatic attraction increases sharply because the electron is closer
So higher ionisation energy

Question 15

Sudden jump in ionisation energies of an atom of 1 element

Answer 15

When the electron is in a shell closer to the nucleus
There is a decrease in distance of electron to nucleus
So increase in electrostatic attraction = increase ionisation energy

Question 16

Ionisation energy trends across periods

Answer 16

ACROSS the period the ionisation energy INCREASES
The number goes up so more energy is required to remove electron

Question 17

Why does ionisation energy INCREASE ACROSS the period?

Answer 17

Increased electrostatic attraction between nucleus and electron
Shielding increases ever so slightly due to more electron-electron repulsion between
But nuclear charge increases thus the radius decreases so more electrostatic attraction which counteracts shielding

Question 18

Why does the atomic radius decrease across the period?

Answer 18

Even though there is no increase in shells
The more protons have greater nuclear charge
So electrons are pulled closer to the nucleus

Question 19

Ionisation energy trend down the group

Answer 19

Going down a group the ionisation energy decreases
So less energy is needed to overcome the electrostatic attraction

Question 20

Why does ionisation energy DECREASE going DOWN the group?

Answer 20

One more quantum shell
And so the electron is at a higher level than the electron for element above
As a result IE decreases
But also experiences more shielding due to electron-electron repulsion as there are more electrons
Furthermore the electron is at a further distance
These overcome increase in nuclear charge.

Question 21

Does the increase in atomic number affect the ionisation trends going down the group?

Answer 21

It would increase ionisation energy because of increased nuclear charge
But the increase in shielding and distance outweigh this thus the ionisation energy decreases

Question 22

Be and B electron configurations

Answer 22

Be = 1s²2s²
B = 1s²2s²2p¹

Question 23

Anomalies in the ionisation energy periodic table trends: Be to B

Answer 23

From Be to B the ionisation energy decreases
Because the singular 2p electron is in a higher energy sub shell than 2s
So it’s easier to remove the outer energy in 2p thus less energy required for B so lower ionisation energy

Question 24

N and O electron configurations

Answer 24

N = 1s²2s²2p³
O = 1s²2s²2p⁴

Question 25

Anomalies in ionisation energy trends in periodic table trends: N to O

Answer 25

There is a decrease in ionisation energy between N and O
Because in the 2p shell of N
The 3 electrons are unpaired
Whereas in 2p of O, 2 electrons are paired
The repulsion between electrons in O makes it easier to remove = decreased ionisation energy

Question 26

Which electron is removed from first then successive ionisation energies?

Answer 26

Electrons in the highest energy levels removed first
Them to the lower energy levels
Which is why electron from 4s is lost before 3p

Question 27

What is the evidence that shows electrons occupy shells of different energy levels?

Answer 27

Shown in atomic emission spectra

Question 28

What is atomic emission spectra and how does it work?

Answer 28

A technique where:
Gaseous atoms are given energy (heating etc)
Theelectrons move to a higher energy level then return, emitting electromagnetic radiation

Question 29

How does atomic emission spectra prove that atoms have different energy levels?

Answer 29

When returning to original energy level, they emit electromagnetic radiation
Which is seen on a spectrum
But only specific frequencies are emitted not a continued spectrum
So perhaps there are fixed energy levels (as shells) rather than as continuous increasing

Question 30

Why is there an increase in magnitude of successive ionisation for one atom?

Answer 30

Because as electrons are removed, the repulsions between electrons are decreasing
So the electrons are at lower energies
Meaning more energy is required to remove them from the orbital (increase in ionisation energy)

Question 31

Is the energy each electron needs to get at the same in a given atom?

Answer 31

Yes regardless do where in the atom it came from
But because some energy levels are at higher levels, less energy is required to get to this point (the ionisation energy) which is effected by nuclear charge, electron repulsion and distance

Question 32

Energy of electron when it has been removed

Answer 32

Once the electron has been removed it is at a certain higher level which is what it was required to get to to be removed

Question 33

Energy of electron when in orbital

Answer 33

Determined by electron repulsion, spin, distance to nucleus and size of nuclear attraction

Question 34

Ionisation energy in terms of the difference between when the electron was lost and when it remained in the orbital

Answer 34

IE = energy of electron when removed - energy of electron when in the orbital

Question 35

In terms of the ionisation energy equation on the location of the electron, what factor is what determines the ionisation energy of that particular electron?

Answer 35

The energy of electron when in orbital (which is determined by SNSS) because the energy once removed is the same for the other electrons in the atom

Question 36

Where does electron-electron affect?

Answer 36

between 2 electrons in the same orbital
Between 2 electrons in the same shell but diff orbital
Between electrons in adjacent shells

Question 37

If the energy or an electron decreases how does that affect the ionisation energy?

Answer 37

Increase it
Because more is added to get it to a certain magnitude for it to be removed from the orbital