What does below science rebus mean?

Ag Ag Ag
Ag SPOON Ag
Ag Ag Ag

If you drop me I’m sure to crack, but give me a smile and I’ll always smile back. What am I?

A mother is 21 years older than her child. In exactly 6 years from now, the mother will be exactly 5 times as old as the child.
Where's the father?

Can you find out which number multiplied by itself will give the output as 12345678987654321?

John bought 150 chocolates but he misplaced some of them. His Father asked him how many chocolates were misplaced.
He gave the following answer to him:
If you count in pairs, one remains
If you count in threes, two remain
If you count in fours, three remain
If you count in fives, four remain
If you count in sixes, five remain
If you count in sevens, no chocolate remains.

Can you analyze the statements and tell us how many chocolates were lost?

What does this below rebus puzzle mean?

A guard is positioned at the one side of the bridge saying ‘A’. His task is to shoot all those who try to leave from ‘A’ to the other side and say ‘B’. He also need to welcome the person who comes from another side ‘B’ to his side ‘A’. The guard comes out of his post every 1 hour and looks down the bridge for any people trying to leave. You are at side ‘A’ and wish to go to another side ‘B’. you also know that it would take 1:45 hr to cross the bridge. How will you cross the bridge?

When is the top of a mountain similar to a savings account?

John replied, when asked how old he was. In 2 years he will be twice as old as he was five years ago.' How old is he ?

With the help clues provided in the image, can you find the 5 digit key?