What does below chemistry rebus means?

You can see three almost identical images below. Can you spot the odd one out from them?

Wednesday, Steve and Pam go to a restaurant to eat lunch. After eating lunch, they pay the bill. But Steve and Pam do not pay the bill. So…who does?

How can a man go eight days without sleep?

On the dull night when the blonde was dozing, she heard an odd clamour and she saw that there was a bizarre man with a gun simply outside her home. So she raced to the telephone to call the police, however, she can't dial 911. Why?

A few friends are enjoying their sea voyage in a boat full of apples. On the way, they felt hungry and thus decided to eat the apples. Together, they ate two dozen of apples. When they have eaten the apples, will there be any change in the water level?

You are given a cube that is made with the help of 10x10x10 smaller cubes summing up to a total of 1000 smaller cubes. You are asked to take off one layer of the cubes.
How many remain now?

Andrew’s doctor gives him three pills and tells him to take one every half hour. How much time will have passed by the time Andrew’s taken all three pills?

Count the squares in the matchstick puzzle below?

John can fit six large chocolate boxes or nine small chocolate boxes into a carton. How many cartons will he require to put sixty-six chocolate boxes into?