Many have heard it, but nobody has ever seen it, and it will not speak back until spoken to. What is it?

What does below chemistry rebus means?

I am looking for a word that change both gender and number when i add the letter 'S'.

What Word am I Looking For ?

Which alphabet is a part of our body?

I am a seven-letter word but if you remove four of my letters I will have one left. What word am I?

I am quite hot but become too cold if you remove the first two letters. What am I?

Two Twins Jack and Jill were standing back to back and suddenly they started running in opposite direction for 4 kilometres and then turn to left and run for another 3 kilometres.

what is the distance between the Baggio twins when they stop ?

What part of Turkey has the most feathers?

I don't get anymore wetter, no matter how much rain falls on me.

Two old friends, Jack and Bill, meet after a long time.

Three kids
Jack: Hey, how are you, man?
Bill: Not bad, got married and I have three kids now.
Jack: That's awesome. How old are they?
Bill: The product of their ages is 72 and the sum of their ages is the same as your birth date.
Jack: Cool..But I still don't know.
Bill: My eldest kid just started taking piano lessons.
Jack: Oh, now I get it.

How old are Bill's kids?