EL8 Spectacular Metals

Question 1

Define ionisation energy

Answer 1

Energy required to remove an electron from an atom, forming a positive ion

Question 2

Define first ionisation energy

Answer 2

Energy required to remove 1 electron from each atom in 1 mole of gaseous atoms

Question 3

How does atomic radius affect ionisation energy?

Answer 3

• as atomic radius increases, I.E decreases, due to weaker nuclear attraction

Question 4

How does nuclear charge affect ionisation energy?

Answer 4

• greater the nuclear charge, greater nuclear attraction, I.E increases

Question 5

How does electron shielding affect ionisation energy?

Answer 5

• inner shells of electrons repel outer electrons, therefore more inner shell means greater shielding, less nuclear attraction therefore lower I.E

Question 6

Why do successive ionisation energies increase?

Answer 6

As electrons are removed, nuclear charge increases, ionic radius decreases, nuclear attraction increases

Question 7

How can a graph showing successive ionisation energies allow you to predict the group of an element?

Answer 7

• there are large jumps between each energy level

Question 8

Define electronegativity

Answer 8

Relative ability of atoms to attract electrons in a covalent bond

Question 9

Does electronegativity increase or decrease across a period? And why

Answer 9

• increases

- atomic radius decreases, stronger nuclear attraction

Question 10

Does electronegativity increase or decrease down a group? And why

Answer 10

Decrease

- atomic radius increases, weaker nuclear attraction

Question 11

What are group 1 elements known as?

Answer 11

Alkali metals

Question 12

What are group 2 elements known as?

Answer 12

Alkali earth metals

Question 13

Do elements in groups 1 and 2 become more or less metallic down group?

Answer 13

• more metallic

- reactivity increases down group

Question 14

Do elements become more or less metallic across a period?

Answer 14

• less metallic

- reactivity decreases across period

Question 15

What is formed when group 2 metals react with water?

Answer 15

Metal hydroxide and hydrogen

Question 16

Give equation for reaction between calcium and water

Answer 16

Ca(s) + H20(l) Ca(OH)2(aq) + H2(g)

Question 17

What is calcium hydroxide used for?

Answer 17

• neutralising acidic soil

Question 18

What is magnesium hydroxide used for?

Answer 18

Neutralising stomach acid

Question 19

What is produced when group 2 elements react with oxygen?

Answer 19

Group 2 oxides

Question 20

Give equation for magnesium and oxygen

Answer 20

2Mg(s) + O2(g) 2MgO(s)

Question 21

What happens when group 2 oxides are dissolved in water?

Answer 21

Aqueous solution of metal hydroxide is produced

Question 22

What is produced when group 2 carbonates undergo thermal decomposition?

Answer 22

Metal oxide and carbon dioxide

Question 23

Give equation of thermal decomposition of calcium carbonate

Answer 23

CaCO3(s) –> CaO(s) + CO2(g)

Question 24

Does thermal decomposition become easier or harder down group and why?

Answer 24

• harder
• smaller ions have greater charge density, therefore greater polarising effect on negatively charged cloud around carbonate ion, therefore carbonate is less stable