What does below chemistry rebus means?

Name a key which is hardest to turn.

A man and a dog were going down the street. The man rode, yet walked. What was the dog’s name?

A B C D E F G H

These are the letters given to you. Now you have to find out the letter that comes two to the right of the letter which is immediately to the left of the letter that comes three to the right of the letter that comes midway between the letter two to the left of the letter C and the letter immediately to the right of the letter F.

There is an English word that can be used up to four times in a row without modifying the spelling and form a valid grammatical sentence.

Do you know what word is that?

Solve below rebus puzzle?

I am the one who remains awake when you sleep. But I need to rest when you awake. Who Am I?

What am I?

Can you find the key in the picture below?

A man is lying dead in a field where no one is around. His head is split open and his legs are disfigured. Near to him, there is an unopened package. No living organism can be found anywhere at the crime scene.

How did he die?