What does the below rebus riddle means?

What is the end of everything?

John: "Hi Teacher, What is your favourite movie ?".
Chemistry Teacher: "Indium Cerium Platinum Iodine Oxygen Nitrogen".
Ten seconds later... John replied I got it.

Do you?

Jim and Sarah are in a long-distance relationship. Jim buys an engagement ring for Sarah and wants to mail it to her. Unfortunately, the only way to ensure the ring will be received is to place a lock on the package. Jim has locks and Sarah has locks, but neither has keys for each other’s locks. How can they make sure the ring isn’t stolen?

John is the son of Jacob.
So,
Jacob is the_____of John's father?

In the given figure, you can see that four match sticks are used to form a square. Can you form five squares by using six matches?

You have a square. What you have to do is cut and reassemble the square such that you create a Red Cross sign that has the same volume as that of the square.

What time is it when an elephant sits on a fence?

Luis Garavito killed Density x Volume.

Who is Luis Garavito ?

I have branches, but no fruit, trunk or leaves. What am I?