Ionisation

Question 1

What is the first ionisation energy

Answer 1

The energy needed to remove one electron from each atom in one mole of gaseous atoms to form one mole of gaseous 1+ ions.

Question 2

What is ionisation

Answer 2

The removal of one or more electrons.

Question 3

What reaction/ process in needed to ionise an atom or molecule

Answer 3

Endothermic reaction.

Question 4

What is the equation for the ionisation of oxygen

Answer 4

O(g) -> O+(g) + e-

Question 5

The lower the ionisation energy, the _____ it is to form an ion.

Answer 5

Easier

Question 6

Factors affecting ionisation energy

Answer 6

1. Nuclear charge - more protons = more positively charged nucleus so electrons have a stronger force of attraction.
2. Distance from nucleus - closer electron - stronger attraction to nucleus.

3 Shielding - Increase in electron number between outer shell and nucleus causes weaker forces of attraction as shielding off the inner electrons happens.

Question 7

What does a higher ionisation energy mean

Answer 7

That there is a higher attraction between electrons and the nucleus due to more protons and so more energy is needed to remove an electron.

Question 8

Why does the ionisation energy of elements down a group decrease

Answer 8

because of shielding; the electron to be removed is getting greater distance from nucleus so weaker force of attraction.

Question 9

Why does the ionisation energy of elements across a period increase

Answer 9

because of more protons being within the nucleus and so that makes a stronger force of attraction between the electrons and the nucleus. this is only right when its elements in the same sub atomic shell or if they aren’t repelling as when it reaches the 4th electron of P, the energy decreases as the electrons are repelling each other so its easier to lose (less energy needed).

Question 10

Why do you need more energy to remove electrons from Ca than K

Answer 10

because there is more protons in Ca and with them being in the same sub shell (4s), it makes it have a stronger force to the nucleus so more energy is required to overcome the proton-electron attraction.

Question 11

Why does the ionisation energy level go down as you go down the periodic table from Mg to Al

Answer 11

despite the nuclear charge increase, it goes down due to the outer electron in Al being in a 3p orbital which is of slightly higher energy than the 3s orbital. it therefore needs less energy to remove electron.

Question 12

Why is there a drop of ionisation energy between phosphorus and sulphur

Answer 12

because phosphorus has each of the 3 3p orbitals containing one electron each whilst sulphur contains one of the 3p with 2 electrons and so them electrons repel each other making it easier to remove an electron from sulphur so the energy to remove it is less.

Question 13

What does successive ionisation energies show

Answer 13

the shell structure.

Question 14

What does successive ionisation energies involve

Answer 14

removing additional electrons. every time you remove an electron, theres a successive ionisation energy.

Question 15

What is second ionisation energy

Answer 15

The energy needed to remove a second electron from each ion in 1 mole of gaseous 1+ ions to form 1 mole of gaseous 2+ ion.

Question 16

Equation for second ionisation energy with oxygen

Answer 16

O+(g) -> O2+ (g) + e-

Question 17

nth ionisation energy equation

Answer 17

X^(n-1)+(g) -> X^n+(g) + e-

Question 18

Why would the energy go down from Mg to Al

Answer 18

because of It being a different sub shell so weaker forces of attraction as further from nucleus.

Question 19

Why would you need more energy from I.e. Na to Mg

Answer 19

same 3S shell
more protons
stronger forces of attraction to nucleus

Question 20

When two electrons are in the same sub shell what does it effect

Answer 20

the energy levels. it makes it easier to lose an electron as they repel so it needs less energy.

Question 21

Why do you need more energy when ion charge increases (+, 2+, 3+)

Answer 21

because it has a positive charge and its attracted to the nucleus more = stronger forces of attraction.

Question 22

Within each cell what increases

Answer 22

the successive ionisation energies.

Question 23

Why does the successive ionisation energies increase within each cell (ions)

Answer 23

because electrons are being removed from an increasingly positive ion (less repulsion so held more strongly by nucleus).