Q. Following statements regarding the periodic trends of chemical reactivity to 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.
Explanation
(d)
In alkali metals reactivity increases down the group as electropositivity increases, but for halogens $F_{2}$ is more reactive as moving down molecular stability increases.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.