Chemistry Form 4: Chapter 4 - Reactivity of Group 1

Reactivity of Group 1 increases when go down the group.

WHY?

• When an alkali metal atom reacts, it loses an electron to form a singly positively charged ion which is a stable noble gases electron arrangement.
• When go down the group, the atomic radius gets bigger due to an extra filled electron shell and the outer electron is further and further away from the nucleus.
• Therefore the outer electron is less strongly held by the positive nucleus as the attractive force is decreased.
• As a result, the outer electron is more easily lost and react more vigorously.
  
  Reaction of Group 1 with water