Explanation:
Given elements:
F, Sr, P, Ca, O, Br, Rb, Sb, Li, S
Elements with the same chemical reactivity will belong to the same group on the periodic table. This implies that elements in the same column will have the same reactivity;
Li and Rb are both alkali metals in group 1
Ca and Sr are both alkali earth metals in group 2
F and Br are halogens in group 7
O and S are group 6 elements
P and Sb are both in group 5 on the periodic table
So these groupings show elements with the same chemical properties.
Answer:
The correct answer is option a.
Explanation:
When aluminum hydroxide reacts with of nitrous acid it gives of aluminum nitrite and of water.

According to above reaction ,when 1 mole of aluminum hydroxide reacts with 3 moles of nitrous acid it gives 1 mole of aluminum nitrite and 3 moles of water.
Hence, the correct answer is option a.