What does below chemistry rebus means?

It's a protector.
It sits on a bridge.
One individual can see directly through it, while others wonder what it hides.

What is it?

I throw two dice simultaneously.

What is the probability of getting a sum as 9 of the two numbers shown?

In The 1st month of this year(the year 2013), I noticed that the date 13-1-13 (13 January 2013) is special.

This date is special as:

Date * Month = Year.

Can you figure out which year of this century has a maximum number of such dates?

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

I am a prime number.
The double of myself is equal to the square of me.

which number am I?

A man says, "Brothers and sisters, have I none, but that man's father is my father's son." Who is that man?

I am working in a bus company. The company recently went under expansion and therefore there was not enough room for all the buses. As a result, twelve buses had to be stored outside.

If the company decides to expand the garage space by forty percent, enough space to accommodate the current buses will be created leaving enough space for twelve more buses if the need arises in future.

Can you calculate the number of buses that the company owns at present?

How can you make the following equation true by drawing only one straight line: 5+5+5=550 ?

Find the next number in the series

12, 20, 40, 72, 116, 172 ?