What does below chemistry rebus means?

If you read clockwise, you can form a word by inserting three missing letters in the picture given below. Can you do it?

Out of four images which one is the odd one out?

You board a train. The train will have to enter a tunnel soon. You are claustrophobic. Which place is the best for you to sit?

How can you throw a ball as hard as you can and have it come back to you even if it doesn't hit anything there is nothing attached to it and no one else catches or throws it.

Can you Find and name the hidden bird in the picture below ?

On one occasion, A Boy collects 71 rupees in form of 20 paise and 25 paise. He collects a total of 324 coins.

Can you tell me how many 20-paisa and 25-paisa he got?

Jenifer is learning to drive her car. She went down a one way lane and in the wrong direction. But she do not break any law.

How come ?

If you had an infinite supply of water and 5-quart and 3-quart pails, how would you measure exactly 4 quarts? What is the least number of steps you need?

A man wants to cross the pit of fire which is 25 feet in length and he has 2 planks(fire resistant) 19 feet in length. How can he cross the pit of fire alive?