What does below chemistry rebus means?

Solve the equation by replacing the alphabet with numbers.

MOM + MOM + NO = BOOK=

I’m light as a feather, yet the strongest person can’t hold me for five minutes. What am I?

What is the largest amount of money that you can possess in change and still if someone asks you for a dollar, you won't be able to give?

While handling a project, the landscaper is asked by the owner of the mansion that he wants four trees in front of his mansion that are exactly equidistant from each other.

How will he do it?

What Time Should the last watch show in the below figure?

Why is 6 afraid of 7?

In my garden, I have many trees but only one of them is the mango tree. In these mango trees, there are some mangoes(as expected).

But after a strong wind, there are neither mangoes on the tree nor on the ground. Explain?

What has lots of eyes, but can’t see?

A prisoner is told: "If you tell a lie, we will hang you and if you tell the truth, we will shoot you." What did the prisoner say to save himself?