Topic 1

Question 1

what is first ionisation energy

Answer 1

the enthalpy required to remove one mole of electrons from one mole of gaseous atoms to produce one mole of unipositive, gaseous ions

Question 2

Factors influencing ionisation energies

Answer 2

Atomic number
The more protons, the more positively charged the nucleus and the more attracted the electrons
Distance from sub shell to nucleus
attraction decreases rapidly with distance
Shielding
as the number of sub shells increase, the electrons feel less attraction towards the nucleus

Question 3

ionisation trend across a period

Answer 3

Increases

The atomic number gets larger
The new electrons are added to the same shell so there is no extra shielding

Question 4

ionisation trend down a group

Answer 4

Decreases

There are more electrons shells separating the nucleus and electron (shielding)
The extra electron shells also means greater distance from the nucleus

Question 5

Drops between groups 2 and 3 (across a period)

Answer 5

the group 3 atom’s electron is in a higher energy orbital so the electron is slightly further from the nucleus
also the extra orbital increases shielding
(override increased nuclear charge)

Question 6

Drops between group 5 and 6 (across a period)

Answer 6

the group 5 sub shell is stable | | | (half sub shell)
the group 6 electron sub shell is less stable and the electron pair already repel each other so it is easier to remove || | |

Question 7

S sub shells

Answer 7

2 electrons

spherical

Question 8

p sub shells

Answer 8

6 electrons

dumbbell shape

Question 9

d sub shells

Answer 9

10 electrons

Question 10

f sub shells

Answer 10

14 electrons

Question 11

if the ionisation energy jump is between 3 and 4..

Answer 11

its atomic number is 8/16

Question 12

order of sub shells

Answer 12

1s 2s 2p 3s 3p 4s 3d

Question 13

electronic configuration determines …

Answer 13

the chemical properties of an element

Question 14

what is periodicity

Answer 14

repeating patterns across different periods

Question 15

melting and boiling point trend across a period

Answer 15

first three elements are metals
Held together by electrostatic forces, these increase across the period (more delocalised electrons and greater charge density) so melting and boiling points increase

the fourth element forms a giant covalent lattice
this has very strong covalent bonds - highest melting point in the period

the fifth sixth and seventh elements are simple molecular structures held by covalent bonds
only weak vdw forces so very low melting and boiling points (still increase)

8th element the noble gas has the lowest melting and boiling points as it is monatomic with weak vdw forces

Question 16

atomic radii across a period

Answer 16

atomic radius decreases (increases down a group)
atomic number increases (positive nucleus) so electrons are pulled closer
extra electrons added to the same shell (no more shells)