The correct option is D.
The hydrogen atoms that are attached to the nitrogen atom in the ammonia molecule are capable of forming hydrogen bond. The hydrogen bond that exist in the ammonia molecule is the reason why it shows higher boiling point compare to the other hydrides. Hydrogen bond occur in ammonia because ammonia is one of the most electronegative elements.
Both aluminum and chlorine have known charges, which are +3 and -1 respectively. To make them cancel each other out in charge, you would need 3 chlorine and for one aluminum, therefore

would be correct
Reaction of Elemental Calcium with Water is as follow,
Ca + 2 H₂O → Ca(OH)₂ + H₂↑
When Sodium Metal is reacted with Water it produces NaOH and eliminates Hydrogen gas as shown in following equation,
2 Na + 2 H₂O → 2 NaOH + H₂↑
In both cases corresponding Hydroxides along with Hydrogen gas is produced.
Answer:0.477 g/ml
Explanation:
Density=(40.14-33.79)/13.3 ml
Density=6.35/13.3
Density=0.477 g/ml