What does below chemistry rebus means?

I am taken from a mine and shut up in a wooden case, from which I am never released, and yet I am used by almost every person. What am I?

Can you place six X (crosses) in below board without making three in a row in any way ?

I have feet, but no legs. Which animal Am I?

A clock loses 10 minutes each hour. If the clock is set correctly at noon, what time is it when it reads 3 PM?

It has horns but can’t beep. It is like to bleat but It is not a sheep. What is it?

In the following series, a set of numbers is progressing with a particular pattern. Can you deduce that pattern and find the missing set?

(2 + 6), (21 + 6), (58 + 6), (119 + 6), ___

A woman lives in a Tall building thirty-six floors high and served by several elevators which stop at each floor going up and down. Each morning she leaves her apartment and goes to one of the elevators. Whichever one she takes is three times more likely to be going up than down. Why?

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

On her drawing table, Sayna lit 12 coloured candles. A few seconds later she blew two candles off.

How many candles Sayna have at the end?