Any particular element can always be identified by its

They can be identified by the amount of protons, electrons, and neutrons.

The physical properties are different ways to identify the element in the periodic table.

Explanation:

The substance which cannot be separated by any types of external forces are called element. In periodic table, these elements are arranged based upon the atomic number with element specific symbols. In order to identify the element, two methods can be used.  

If the symbol or atomic number is given, the element can be identified by correlating it with the periodic table, on the other hand, if the element is given it can be identified by the physical properties such as color, texture, flame test, etc.  

cats appear to have glowing cat eyes because the back of their eyeballs includes a special reflective surface called the tapetum lucidum. this lets them see better during the night, giving them a much better vision.