What does below chemistry rebus means?

What word begins and ends with an E, but has only one letter?

There are three boxes which are labeled as Rs100, Rs150, and Rs200. One box contains two notes of Rs. 50. The second box contains one note of Rs50 and one note of Rs100 The third box contains two Rs. 100 notes. All boxes are labeled incorrectly.

What is the minimum number of boxes you must check in order to label all boxes correctly?

What goes up but never comes down?

Can you spot what's wrong with the following sentence?

PETER WAS ANGRY AT
HIMSELF BECAUSE HE
ACCIDENTALLY LEFT THE
THE KEYS TO HIS CAR
AT HIS FRIEND'S HOUSE.

If your uncle’s sister is not your aunt, what relation is she to you?

Remove two matchsticks to make the below equation correct.

John and Jenni are a married couple. They have two kids, one of them is a girl. Assume safely that the probability of each gender is 1/2.
What is the probability that the other kid is also a girl?

Hint: It is not 1/2 as you would first think.

My friends called me Iron59 because my parents are a chemist and a mathematician. What is my real name?

Can you decipher the following common phrase?

T M C
A U O
H S M
W T E