What does below chemistry rebus means?

By including only four matchsticks in below picture, you have to make "Four Triangles And Two Squares"

Using Only Five 5's and any mathematical operator make sum as 37

A woman is sitting in her hotel room and hears a knock at the door. She opens the door to see a man whom she’s never met before. He says, “I’m sorry, I have made a mistake, I thought this was my room.” He then goes down the corridor and into the elevator. The woman goes back into her room and calls security. What made the woman so suspicious of the man?

Can you find out the number of the parking space in which the car is parked?

If,

Akriti = 631
Levis = 521
Sroti = 521
Aneel = 533
Then,
Sunil =?

If eleven plus two equals one, what does nine plus five equal?

You need to complete the maze by entering from the entrance marked below in the figure near the yellow circle, bottom left and leaving from the exit point near the green circle, bottom middle.

Rule of Game: You can move only by exchanging green and yellow circles.

How many pluses should we put between the digits of 987654321 to get a total of 99, and where?

Always in you, Sometimes on you;

If I surround you, I can kill you.

What am I?