Question

Following statements regarding the periodic trends of chemical reactivity of the alkali metals and the halogens are given. Which of these statements gives the correct picture ?

• A. The reactivity decreases in the alkali metals but increases in the halogens with increase in atomic number down the group
• B. In both the alkali metals and the halogens the chemical reactivity decreases with increase in atomic number down the group
• C. Chemical reactivity increases with increase in atomic number down the group in both the alkali metals and halogens
• D. In alkali metals the reactivity increases but in the halogens it decreases with increase in atomic number down the group

Answer 1

Answer: (D)

In alkali metals the reactivity increases but in the halogens it decreases with increase in atomic number down the group

Answer 2

Alkali metals reactivity increases down the group as electropositivity increases, but for halogens $F_{2}$is more reactive as moving down molecular stability increases.