EL - ionisation and group 2 trends

Question 1

1st ionisation for group 2

Answer 1

Ionisation energy decreases down group due to atomic radius increasing and shielding increasing

Question 2

ionisation energy

Answer 2

minimum amount of energy required to remove one mole of electrons from one mole of atoms in gaseous state

Question 3

ionisation energy is always…

Answer 3

endothermic
positive

Question 4

shielding

Answer 4

The more shells between the positive nucleus and the negative electron being removed, the less energy is required to remove it due to weaker attraction

Question 5

atomic radius

Answer 5

The bigger the atom, the further the positive nucleus from the outer negative electrons. This means there is a weaker attractive force and it is easier to remove the electron

Question 6

nuclear charge

Answer 6

The more protons in the nucleus, the bigger the attraction between the nucleus and the outer electrons so more energy required to remove the electron

Question 7

1st ionisation trend for period 3

Answer 7

Ionisation energy increases across a period
Increased nuclear charge
Shielding remains the same across

Question 8

Group 2 reaction with water

Answer 8

forms the base: metal hydroxide
Reactivity increase with water, no reaction with Be,
Reactivity increases because the atom gets larger down the group so electrons are further from the nucleus so easier to remove

Question 9

Group 2 reaction with oxygen

Answer 9

Base: metal oxides
Forms a white solid

Question 10

What is formed when metal hydroxides are added to water and why

Answer 10

Alkaline solution
Oxides react readily with water to make hydroxides which dissociate to form OH- ions

Question 11

Trend of alkaline solutions down group 2

Answer 11

They become more strongly alkaline as we go down the group as hydroxides become more soluble

Question 12

Group 2 solubility trend

Answer 12

Group 2 carbonates and hydroxides have opposite solubility as we go down the group
Carbonates decrease in solubility
Hydroxides increase in solubility

Question 13

What happens during thermal decomposition

Answer 13

carbonates break down into metal oxides and carbon dioxide

Question 14

Carbonates stability trend down group 2

Answer 14

Become more thermally stable
Carbonate ions have a large electron cloud that can be distorted when nearby positive group 2 metal ions

Question 15

What happens to the +2 charge in group 2 metal ions as it goes down the group

Answer 15

They become larger so the charge becomes more spread out and it has a lower charge density

Question 16

How to identify a stable carbonate

Answer 16

less distortion = more stable carbonate
Higher charge density = more distortion to the carbonate ion