Copper ions-releasing IUDs are more efficient than non-medicated methods. Why?

Why alkenes are more reactive than alkanes?

Name any two copper releasing IUDs.

Why ethylamine is more basic than ammonia

Why is an amide more acidic than amine ?

Explain why: Heating systems based on circulation of steam are more efficient in warming a building than those based on circulation of hot water.

Respriatory system of cockroach is formed of spiracels and tracheal intercom. Why it is said to be more efficient than that of earthworm? Why inspritation of cockraoch is said to be a passive process while it is an active process in man?