Point out the incorrect statement regarding $Be$ (Group-$IIA$):

How many of the following oxides are amphoteric?
$BeO, ZnO, Sb_2O_3, CO, CaO, SO_2, SO_3$

Milk of magnesia is

Match the compounds in List-$I$ with their chemical formulas in List-$II$ and select the correct answer using the codes given below:
List-$I$ (Compounds) | List-$II$ (Formulas)
$(A)$ Plaster of Paris | $(i) \, CaSO_4 \cdot 2H_2O$
$(B)$ Epsomite | $(ii) \, CaSO_4 \cdot \frac{1}{2} H_2O$
$(C)$ Kieserite | $(iii) \, MgSO_4 \cdot 7H_2O$
$(D)$ Gypsum | $(iv) \, MgSO_4 \cdot H_2O$

Match column-$I$ with column-$II$ :

Column-$I$	Column-$II$
$(a)$ Calcium	$(p)$ Crimson red
$(b)$ Barium	$(q)$ Brick red
$(c)$ Strontium	$(r)$ Apple green
-	$(s)$ Yellow

Which of the following substances is the least soluble in water?