Step-by-step explanation:
1A:
We have to find the bases from these compounds: K₂O, NaH, HNO₂ and CsOH.
HNO₂ is the formula for nitrous acid, then it is an acid, not a base. K₂O is the formula for potassium oxide, it's a basic oxide, but an oxide. CsOH is cesium hydroxide, it is a base. And NaH is sodium hydride. Sodium hydride acts as a strong base in many reactions.
1B:
Lithium hydroxide is a strong base, when dissolved in water if forms ions. The bond between the ion Li+ and the anion OH- is ionic. Then this compound is an ionic solid.
Answer:
1A. a) K₂O and d. CsOH
1B. c) ionic solid.