Answer:
Option C: sodium and potassium
Explanation:
Elements in same group having same properties. In given option Only C is the correct option because sodium and potassium are present in same group i.e, group 1 and thus shows similar reactive properties. Bothe are alkali metal and have one valance electron. These are very reactive and can not found in free state in nature but present in compounds.
They react with halogens and form salts.
2Na + Cl₂ → 2NaCl
2K + Cl₂ → 2KCl
All other options are incorrect because,
Option A = Fluorine and neon
Both are present in different group. Fluorine is present in group 17 and neon in group 18 thus their reactivity is not similar.
Option B = Hydrogen and helium
Both are present in different group. Hydrogen is present in group 1 and helium in group 18 thus their reactivity is not similar.
Option D: Aluminum and chlorine
Both are present in different group. Aluminum is present in group 13 and chlorine in group 17 thus their reactivity is not similar.
All these three options are incorrect.
