What does below chemistry rebus means?

A maths symbol is hidden in the below Bar Graph. Can you decipher it?

What brings you down but never up?

Look at the below sequence of letters and tell us what the next letter should be:

O T T F F S S ?

John’s parents have three sons: Snap, Crackle, and what’s the name of the third son?

John was a very careless driver, so his owner Jacob gave him an offer that he will get an incentive of Rs.30 for every bottle box he delivered without breaking it and he will be charged Rs.90 for every bottle box he broke. Jacob gave John 100 bottles-box to deliver. After delivery, Jacob paid John Rs.2400. How many bottles-box did John break?

How many letters are in the alphabet?

A man is approaching a broad and barren land. He has a package with him. If somehow, he is unable to open the package before reaching the land, he will die.

Can you guess what is present in the package?

In the given figure, move three matchsticks so that the resulting figure contains two rectangles.

Two trains start at the same time, one from Bangalore to Mysore and the other from Mysore to Bangalore. if they arrive at their destinations one hour and four hours respectively after passing one another, how much faster is one train running than the other?