What does below chemistry rebus means?

Below the four parts have been reorganised. The four partitions are exactly the same in both arrangements. Why is there a hole?

Solve the mathematical equation in the picture below.

By including only four matchsticks in below picture, you have to make "Four Triangles And Two Squares"

I go up and I go down.
I go up towards the beautiful sky and down toward the green ground.
I am present tense.
I am past tense too
Children love me.

Who Am I?

what one word does the below rebus identifies?

I’m tall when I’m young, and I’m short when I’m old. What am I?

Can you find out the total number of triangles in the given figure?

It's a 7-letter word.
If we remove 1 letter from it, it remains the same.
If we remove 2 letters from it, it remains the same.
If we remove 3 letters from it, it remains the same.
If we remove all the letters from it, still it remains the same.
What is it?

What do you get if you add 2 to 100 four times?