11. GROUP 2

Question 1

Why is there a general increase in reactivity from Mg to Ba

Answer 1

• ionisation energies decrease as it becomes easier to lose the electron
• atomic radius increases as there are more shells so there is increased shielding
• electrons are less attracted to the nucleus
• activation energy decreases

Question 2

Why do melting points decrease from Mg to Ba

Answer 2

• strength of metallic bonding decreases as cation size increases
• and number of delocalised electrons remains the same so charge density of cation decreases
• increased shielding so less attraction between cation and delocalised electrons

Question 3

Functions of calcium carbonate

Answer 3

• limestone to provide useful rocks for building
• marble used in building materials to make tiles
• cement