Assume you are walking on a street and that you find a piece of rock, the next question is which element is it ? Definitely by looking at it its usually not possible to determine what exactly it is.
If you google how to identify an element , the results always point to the periodic table and say that by using the atomic number we can identify the element. And when you search how to find atomic number it again points to periodic table and says by looking at the table we can find the atomic number of a element. Well we are in a loop right now. No where the results tell how to take a physical object that you found randomly on earth and identify what it is.
After searching for quiet a bit, it was found that there is indeed a method which we need to use to determine what element it is exactly. That method is called “Elemental analysis ” .