What does below science rebus mean?

Ag Ag Ag
Ag SPOON Ag
Ag Ag Ag

Find the value of "?" in the ball picture Riddle below:

There is a square of a particular number which when doubled, becomes 7 more than its quarter.

Can you find the number?

A boy was locked in a room by some robbers. All that is in the room is a piano, a calendar, and a bed. The room is locked from the outside. What does he eat, drink, and how does he escape and get out?

What is a word made up of 4 letters, yet is also made up of 3. Sometimes is written with 9 letters, and then with 4. Rarely consists of 6, and never is written with 5.

How many sides does a circle have?

Use only one mathematical symbol and all numbers (0-9) to get a sum of 99

You need to move three matchsticks to form three squares. Can you do it?

Prove that the below maths equation is true.

8 + 8 = 91

You can hear me, but you can't touch or see me.

What am I?