Ammonia is more easy to liquefy than oxygen, then which of the following is true about oxygen as the reason for this fact?

Which of the following is//are true for oxygen.

Which of the following is//are true for oxygen.

Oxygen is difficult to liquify as compared to ammonia, then which of the following is true about oxygen as the reason for this fact?

Ammonia is more soluble than oxygen in water. Why ?

Which of the following tissues requires more oxygen ?

Which of the following fact is /are true about chlorine ?