What does below chemistry rebus means?

John replied, when asked how old he was. In 2 years he will be twice as old as he was five years ago.' How old is he ?

In a stable, there are men and horses. In all, there are 22 heads and 72 feet. How many men and how many horses are in the stable

How far can you walk into the woods?

Three brothers Jacob, John, and James live in Mexico City. The product of the ages of these brothers is 175. Jacob and John are twins. How old is James?

If eleven plus two equals one, what does nine plus five equal?

What is the four-digit number in which the first digit is one-third the second, the third is the sum of the first two, and the last is three times the second?

Irene killed hundreds of people mercilessly and yet the police were not able to put her behind the bars. Why?

what does the below math rebus puzzle mean?

I have feet, but no legs. Which animal Am I?