What does below chemistry rebus means?

Which is faster, Heat or Cold ? Explain.

What can you see in the middle of March and April that you can never see in any other month?

On the dull night when the blonde was dozing, she heard an odd clamour and she saw that there was a bizarre man with a gun simply outside her home. So she raced to the telephone to call the police, however, she can't dial 911. Why?

The doctor prescribed you to take one pill from the bottle every half an hour. The bottle is now left with only three pills.

How long do you think you have before you run out of pills?

A train full of passengers goes through a tunnel. When the train comes out from the other end, there is no single person on the train.

How did it happen?

Can you solve below mathematical equation?

2^1234 - 2^1233

f you were running a race, and you passed the person in 2nd place, what place would you be in now?

Take number 1000 and then add 20 to it.
Now add 1000 one more time.
Now add 30.
Now add 1000 one more time.
Now add 40.
Now add 1000 one more time.
Now add 10.

What is the total?

Solve the equation in the image by looking at the pattern closely.