What does below chemistry rebus means?

Solve the mathematical equation in the picture below.

Can you find the odd number in the following?

2716, 4135, 5321 and 7145

How old is your son? asked a man to his neighbour. My son is five times as old as my daughter and my wife is five times as old as my son. I am twice as old as my wife whereas my grandmother, who is celebrating her eighty-first birthday is as old as all of us put together.

How old is the man's son ?

Can it be possible to build a house that has all its four walls facing towards the South?

Create a number using only the digits 4,4,3,3,2,2,1 and 1. So i can only be eight digits. You have to make sure the ones are separated by one digit, the twos are separated by two digits the threes are separated with three digits and the fours are separated by four digits

Why is 6 afraid of 7?

What has one eye, but can’t see?

Identify The phrase in the picture.

A new Engineering building containing 100 offices had just been completed. John was hired to paint the numbers 1 to 100 on the doors. How many times will John have to paint the number nine (9)?