What is both possible and impossible at the same time?

What does below chemistry rebus means?

A boy purchased a book from a bookkeeper and gave him $100.
The cost of the book is $50 but the bookkeeper has no change, so he gets the change from the next shop and returns the boy his $50.

After some time the next shopkeeper came with the $100 note and told the bookkeeper that the note was a fraud, so he took the money back.

How much loss did the bookkeeper face?

I possess a head

I flaunt a tail

But I don't have mouth or legs

Can you find out who I am?

I have cities, but no houses. I have mountains, but no trees. I have water, but no fish. What am I?

James bond was pushed out of an aeroplane without any parachute.
He survived, How come?

using four eights (8) and a one (1) and one mathematical symbol , create the number 100

The current time can be represented by below textual rebus.

0
=========
B.Sc
LLB

Can you tell us the current time?

The sum of a mother, her baby and her dog's weight is 170 Kg. How much does the baby weigh if the mother weighs 100 kg more than the combined weight of the baby and the dog, and the dog weighs 60 per cent less than the baby?

Can you spot the man between the coffee bean in the picture below ?