1.1 atomic structure- electron config

Question 1

what is an orbital

Answer 1

region of space in which electrons move

Question 2

what are the s and p orbital shapes

Answer 2

s=spherical
p=dumbbell

Question 3

how many electrons can each orbital hold

Answer 3

s=2
p=6
d=10

Question 4

what is copper’s electron structure

Answer 4

1s1 2s2 2p6 3s2 3p6 3d5 4s1
-by having one electron in the 4s subshell, it can have a half full 3d subshell which is more stable when half/completely full

Question 5

what is chromium’s electron structure

Answer 5

1s1 2s2 2p6 3s2 3p6 3d10 4s1
-by having one electron in the 4s subshell, it can have a full 3d subshell which is more stable when half/completely full

Question 6

why is aluminium a p-block element

Answer 6

its highest energy electron is in a p-orbital

Question 7

what is the first ionisation energy

Answer 7

energy needed to remove 1 mole of electrons from 1 mole of atoms in their gaseous state, to form 1 mole of +1 ions in their gaseous state
X(g)–>X+(g) + e-

Question 8

what is the second ionisation energy

Answer 8

energy needed to remove 1 mole of electrons from 1 mole of +1 ions in their gaseous state, to form 1 mole of +2 ions in their gaseous state
X+(g)–>X2+(g) + e-

Question 9

3 factors affecting the size of ionisiation energies

Answer 9

-as atomic radius increases, force of attraction between valence electrons+nucleus decreases
-greater number of protons=greater force of attraction between valence electrons+nucleus
-valence electrons are repelled by inner shell electrons. This shielding effect decreases attraction between valence electrons+nucleus

Question 10

why do successive ionisation energies increase in each shell

Answer 10

electrons are being removed from an increasingly positive ion
there’s less repulsion amongst remaining electrons, so they’re held more strongly by the nucleus

Question 11

what are the big jumps in ionisation energy graphs

Answer 11

happens when there’s a new shell broken into- an electron is being removed from a shell closer to the nucleus

Question 12

how to work out the group of the element from an ionisation energy graph

Answer 12

count how many electrons are removed before the first big jump

Question 13

how can ionisation energy graphs predict the electron configuration of an element

Answer 13

from right to left, count how many electrons there are before each big jump to find the number of electrons in each shell

Question 14

what happens to ionisation energy across a period

Answer 14

-increases
reasons:
-more protons in nucleus
-atomic radius decreases
-same amount of shielding

so more attraction between nucleus and valence electron

Question 15

what happens to ionisation energy down a group and when moving into a new period

Answer 15

-decreases
reasons:
-atomic radius increases so valence electron is further from nucleus
-more shielding as there are more electron shells

so more attraction between nucleus and valence electron

Question 16

why are there dips in ionisation energies across a period eg. Mg->Al

Answer 16

-in Al, electron is removed from p orbital
-which is higher in energy/ shielded by 3s
-so its lost more easily

Question 17

why are there dips in ionisation energies across a period eg. P->S

Answer 17

-in S, there are paired electrons in p orbital
-paired electrons repel

Question 18

explain the pattern in the first ionisation energies from lithium to neon (period 2) (6)

Answer 18

-generally, first IE increases across a period
-as there are more protons in the nucleus and electrons are in the same energy levels so there is the same amount of shielding
-leads to more attraction between valence electrons and nucleus
-drop from beryllium to boron (B has lower IE)
-boron’s highest energy electron is in the p-orbital whereas beryllium’s highest energy is in the s-orbital
-boron’s highest energy electron is shielded by the 2s subshell, so it is more easily removed
-2nd drop from nitrogen to oxygen (O has lower IE)
-oxygen has a pair of electrons in its 2p subshell, which experiences repulsion so it is easier to remove

Question 19

why is the ionisation energy of every element endothermic

Answer 19

heat energy needed to overcome attraction between electron and nucleus

Question 20

which elements in period 2 and 3 break the trend

Answer 20

Boron
Oxygen
Aluminium
Sulfure

BOAlS