What does below chemistry rebus means?

What can you catch but never throw?

What three numbers, none of which is zero, give the same result whether they’re added or multiplied?

An equation has been laid down using a few matchsticks. However, as you can see, the equation is not correct. Can you correct the equation if you are allowed to add or remove 5 matchsticks?

The captain of a ship is telling you an interesting story and then poses a question. He says, “I have travelled the oceans far and wide. One time, two of my sailors were standing on opposite sides of the ship. One was looking west and the other one east. And at the same time, they could see each other clearly. Can you tell me how that was possible?”

Which three-digit number, made of consecutive digits, like 567, is 2 less than a cube and 2 more than a square?

As easy as you can get into me, it is as hard to get out of me.

Do you know what I am?

They are the five precious gems of an everyday sort and all can be found on a Tennis Court. Who are they?

Why is it very easy to weigh a fish?

An explorer goes on an exposition in the jungle. He sets up camp in the middle of the jungle. The next morning he sees something with a head and a tail, but he is not afraid. What did he see in his bag?