What does below chemistry rebus means?

Baseball bat and ball cost $100. If the bat cost $99 more than the ball, what is the cost of each?

A tree doubled in height each year until it reached its maximum height over the course of ten years. How many years did it take for the tree to reach half its maximum height?

I am a type of room you cannot enter or leave. Raised from the ground below, I could be poisonous or a delicious treat. What am I?

In the below-given picture of a pretty girl, there is something wrong. Can you find out what it is?

There were three women in all the swimming costumes!
One was happy and the other two were sad!
The happy one was crying and the sad ones were smiling.
Why was this?

There’s a girl who has a large family. She has an equal amount of brothers and sisters, but each brother only has half as many brothers and sisters. What’s the correct amount of brothers and sisters?

What word does this rebus represent?

meta meta
meta meta

Solve the mathematical equation in the picture below.

If an electric train is travelling south, then which way is the smoke going?