What does below chemistry rebus means?

I know a ten-letter word in the English language which can be typed using only the top rows of the computer keyboard.

A mother bought three dress for her triplets daughters(one for each) and put the dresses in the dark. One by one the girls come and pick a dress.
What is the probability that no girl will choose her own dress?

Trying to tease Birbal, Akbar gave him one gold coin and ask him to buy
* something for him to eat
* something for him to drink.
* something to feed the cows
* something to plant in the garden
and most important you need to buy only one thing.

What must Birbal buy to silence Akbar?

What is the riddle which can be asked all day with a different correct answer each time.

When it is alive we sing, when it is dead we clap our hands. What is it?

At a bar, three friends, Mr Green, Mr Red and Mr Blue, were having a drink. One man was wearing a red suit; one a green suit; and the other a blue suit. 'Have you noticed,' said the man in the blue suit, 'that although our suits have colours corresponding to our names, not one of us is wearing a suit that matches our own names?' Mr Red looked at the other two and said, 'You're absolutely correct. What colour suit is each man wearing?

If "P" means "-", "Q" means "/", "R" means "+", and "S" means "*" then find the value of the following:

21 Q 7 R 9 S 10 P 13

I am the beginning of everything, the end of everywhere. I'm the beginning of eternity, the end of time and space. What am I?

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