Chem topic 3 PPQs got wrong

The reactivity of the Group 2 elements Mg–Ba increases down the group. Explain why

increasing size

atomic radius increases OR more shells OR more (electron) shielding

Attraction

Nuclear attraction decreases OR (outer) electrons experience less attraction

Ionisation energy

ionisation energy decreases OR less energy needed to remove electrons

Write an equation with state symbols that accompanies the standard enthalpy change of atomisation of iodine

(6)

The reaction of barium with bromine is more vigorous than the reaction of calcium with bromine. Explain why. (3)

Atomic radius

• Ba has a greater atomic radius than Ca OR Ba has more shells OR Ba has more shielding

Attraction

• nuclear attraction is less in Ba OR outer electrons in Ba are less attracted to the nucleus OR increased distance/shielding in Ba outweighs increased nuclear charge

Ionisation energy

• ionisation energy of Ba is less OR outer electrons in Ba are less attracted to nucleus OR easier to remove outer electrons in Ba

(5)

• metallic bond or attraction between the electrons and positive ions/cations

• bonds are strong/require a lot of energy to break AND high melting point

• Delocalised electrons move AND good conductivity

Why are silicon, carbon, oxygen and chlorine all classified as p-block elements? (1)

Highest energy electrons in a p orbital/p sub shell

• hydrogen

• helium