What does below chemistry rebus means?

What is the fastest way to double your money?

I know a 5-digit number having a property that With a 1 after it, it is three times as large as it would be with a one before it.

Guess the number?

John named his first son Alpha, second Beta, third Charlie and fourth Delta. What is the fifth son's name?

Look at the below sequence of letters and tell us what the next letter should be:

O T T F F S S ?

What does the below image rebus riddle means ?

Which English verb becomes past tense just by rearranging the letters?

I have lakes with no water, mountains with no stone and cities with no buildings. What am I?

A person was killed at a house party. When the police arrive, there are six people present in the house who are the friends of the victim. The name of the friends is Rohit, Aman, Nick, Gagan, and Randy.

Near the dead body, they find a few numbers written with blood by the victim on the floor. The numbers are 8, 5, 4, and 11.

The police arrests one of the friends for the murder. Whom did they arrest and why?

Two friends Smith and Andrew were talking about the bravery of their families. Smith told great stories about his courageous grandfather who fought for Britain in "World War I". Andrew told that his grandfather was so brave that in 1919 just after the war he was honoured with a bravery medal with the words "For our Courageous Soldiers In World War I" embedded into it. Smith knows that his friend is lying. How?