1.2 - Basic ideas about atoms - Ionisation energy

Question 1

What are the four different sub shell letters 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 are the three factors that ionisation energy depends on?

Answer 15

nuclear change
electron shielding
atomic radius

Question 16

what is the effect of nuclear charge/actual nuclear charge on ionisation energies?

Answer 16

the greater the nuclear charge, the greater the attractive force on the outer electon

Question 17

What is the effect of shielding effect on inner electrons?

Answer 17

the more filled inner subshells there are, the smaller the attractive force on the outer electron so IE lower and ENC decreases

Question 18

What is the effect of the size of the atom?

Answer 18

The greater the distance, the smaller the attractive force on the outer electrons

Question 19

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

Answer 19

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

Question 20

what do the peaks on a successive ionisation graph mean?

Answer 20

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

Question 21

what do the troughs in a successive ionisation graph mean?

Answer 21

group 1

Question 22

what does the successive ionisation graph go up in?

Answer 22

periods

Question 23

what happens to first ionisation energies generally across periods?

Answer 23

they increase because the actual nuclear charge is increasing but there is not much change in shielding

Question 24

what happens to first ionisation energies generally down groups?

Answer 24

decrease bc outer electron has increased shielding from inner electrons and is further from nucleus

Question 25

what happens between Be to B?

Answer 25

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 26

what happens between N to O

Answer 26

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

Question 27

what happens from He to Li?

Answer 27

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

Question 28

What happens from He to H?

Answer 28

since helium has a greater nuclear charge in the same subshell so little extra shielding

Question 29

Explain why it is unlikely that stable compounds containing B3+ ions can exist.

Answer 29

Barium is in group two and has two outer electrons too much energy is needed to removed a third electron

Question 30

What are the three factors which cause successive ionisation energies to always increase?

Answer 30

effective nuclear charge less repulsion atomic radius

Question 31

How does effective nuclear charge cause successive ionisation energies to increase?

Answer 31

- there is a greater effective nuclear charge as the same number of protons are holding fewer and fewer electrons

Question 32

How does electron-electron repulsion cause successive ionisation energies to increase?

Answer 32

- as each electron is removed there is less e-e repulsion and each shell will be drawn in slightly closer to the nucleus

Question 33

How does atomic radius cause successive ionisation energies to increase?

Answer 33

- as the distance of each electron from nucleus decreases the nuclear attraction increases

Question 34

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

Answer 34

- 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 35

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

Answer 35

- 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 36

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

Answer 36

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