Question

How we write chemical formula?
Pls explain me ​

Answer 1

Answer:

There's a particular way of writing what's in a molecule called a chemical formula. The chemical formulae for all the elements that form each molecule and uses a small number to the bottom right of an element's symbol to stand for the number of atoms of that element. For example, the chemical formula for water is H2O.

Answer 2

Answer:

An expression which states the number and type of atoms

present in a molecule of a substance.

Chemical formulas such as HClO4 can be divided into empirical formula, molecular formula,  

and structural formula. Chemical symbols of elements in the chemical formula represent the  

elements present, and subscript numbers represent mole proportions of the proceeding  

elements. Note that no subscript number means a subscript of 1.

From a chemical point of view, an element contained in the substance is a fundamental  

question, and we represent the elemental composition by a chemical formula, such as H2O for  

water. This formula implies that the water molecules consist of 2 hydrogen, and 1 oxygen  

atoms. The formula H2O is also the molecular formula of water. For non-molecular substances  

such as table salt, we represent the composition with an empirical formula. Sodium chloride is  

represented by NaCl, meaning that sodium and chlorine ratio in sodium chloride is 1 to 1.  

Again, the subscript 1 is omitted. Since table salt is an ionic compound, the formula implies that  

numbers of Na+ ions, and Cl- ions are the same in the solid. The subscript numbers in an  

empirical formula should have no common divisor.