Ionisation energy

Question 1

What are the four different sub shell eltters and how many orbitals do they have? What is the maximum number of electrons each orbital can hold?

Answer 1

1. s has 1 orbital and holds max 2 electrons
2. p has 3 orbitals and holds max 6 electrons
3. d has 5 orbitals and holds max 10 electrons
4. f has 7 orbitals and holds max 14 electrons

Question 2

define ‘orbitals’

Answer 2

is a volume of space around the nucleus where an electron is likely to be found

Question 3

what is spin pairing?

Answer 3

when an orbital contains two paired up electrons they spin in opposite directions

Question 4

what is the shape of s orbitals?

Answer 4

a spherical shape

Question 5

what is the shape of p orbitals?

Answer 5

a dumb-bell shape

Question 6

why does 4s come before 3d?

Answer 6

it has a lower energy than 3d so it’s filled before 3d is.

Question 7

what are the exceptions to the 4s before 3d rule?

Answer 7

Copper (Cu) and Chromium (Cr) as they donate one electron from 4s to the 3d

Question 8

What region on the periodic table is the s sub shell?

Answer 8

Group 1 and 2

Question 9

What region on the periodic table is the p sub shell?

Answer 9

Group 3-8

Question 10

What region on the periodic table is the d sub shell?

Answer 10

transition metals

Question 11

How do you write the electronic configuration of ions?

Answer 11

remove or add electrons from the highest energy occupies sub-shell
e.g
Mg -> Mg2+
1s²2s²2p^63s² -> 1s²2s²2p^6

Question 12

Define ionisation energy

Answer 12

The energy require to remove one mole of electrons from one mole of gaseous atoms to form one mole of ions with a single positive charge

Question 13

Write the equation K(g) -> K+(g) + e- for the second ionisation energy?

Answer 13

K+(g) -> K2+(g) + e-

Question 14

Describe the main features of the graph and explain them

Answer 14

electrons are being removed closer to the nucleus, removing an electron from an increasingly positive ion
Big jumps= change in shell closer to the nucleus

Question 15

What is the effect of actual nuclear charge?

Answer 15

more protons=greater attraction so harder to remove electrons

Question 16

What is the effect of shielding effect on inner electrons?

Answer 16

inner electrons shield the outer electrons from the pull of the nucleus os IE lower and ENC decreases

Question 17

?What is the effect of the size of the atom?

Answer 17

The larger the atomic size, the smaller will be the ionization energy
in a large atom the electrons are further from the pull of the nucelus so easier to remove

Question 18

What is the effect of the type of electron being removed (spdf)?

Answer 18

the same quantum shell there is a difference in energy between the spdf electrons

Question 19

what are the peaks on a successive ionisation graph mean?

Answer 19

noble gases, they don’t want to lose any electrons

Question 20

what do the troughs in a successive ionisation graph mean?

Answer 20

group 1

Question 21

what does the successive ionisation graph go up in?

Answer 21

periods

Question 22

what happens to first ionisation energies generally across periods?

Answer 22

they increase because the actual nuclear charge is increasing so there is a greater attraction for the electrons

Question 23

what happens to first ionisation energies generally down groups?

Answer 23

decrease in first ionisation energies down groups due to increased atomic radius so outer electrons is further from the nucleus
- less attraction and greater shielding by inner electrons so effective nucleus charge decreases

Question 24

what happens between Be to B?

Answer 24

1s2 2s2 -> 1s2 2s2 2p1
it’s easier to remove as in a sub shell further from the nucleus’s and therefore more shielding so the effective nuclear charge decreases and ionisation energy decreases

Question 25

what happens between N to O

Answer 25

1s2 2s2 2p3 -> 1s2 2s2 2p4
- now paired up so repulsion makes it easier to remove therefore ionisation energy decreases

Question 26

what happens from He to Li?

Answer 26

1s2 -> 1s2 2s1
- a new shell further from the nucleus so shielding increases, effective nuclear charge decreases and ionisation energy decreases

Question 27

By referring to ionisation energies, explain why stable compounds containing K2+ ions are unlikely to form.

Answer 27

The ionisation energy needed to remove one electron from the 3p subshell is very high.
This is due to having a full and stable 3p subshell.

Question 28

what might the reasons for a sharp change in an successive ionisation energy graph be.

Answer 28

• sharp rises due to the electrons being removed from the inner shell closest to the nucleus
• sharp rises due to electron removed from a shell closes to the nucleus with less shielding

Question 29

if asked to describe the way in which electrons are arranged in atoms, how would you go about it?

Answer 29

• talk about how the electrons occupy atomic orbitals within the shells (eg first shell has s orbital, second has s and p)
• how many electrons occupy the orbitals
• spin pairing
• orbitals of the same type are grouped together (eg 3p orbitals in an elements subshell)

Question 30

When comparing the first three ionisation energies of two different atoms, eg Ca+ and K+, what would you talk about?

Answer 30

• value of the first and third IE energy
• value of the second IE energy