Writing the Formula of an Inorganic Salt

Organic chemistry deals with compounds of carbon.
Inorganic chemistry deals with compounds of any other element.
One of the earliest known classes of inorganic compounds were salts.
Salts are binary, ionic compounds, that is, salts are made up of two ions:

• a positively charged ion called a cation
• a negatively charged ion called an anion 

The International Union of Pure and Applied Chemistry (IUPAC) is establishing rules to help us name, and write the formula, for compounds.
In an earlier tutorial we looked at how we name inorganic salts, in this tutorial we look at how to write the formula of an inorganic salt.

Naming Salts

How do you name a salt?
There are several different ways to name salts (binary inorganic ionic compounds).
The most common method used in school as an introduction to naming inorganic compounds is based on compositional nomenclature.
AUS-e-TUTE has a step-by-step guide to how to name a salt if you know the formula of the salt:
https://www.ausetute.com.au/namiform.html

Writing Chemical Formula

The chemical formula for the ammonium ion is NH₄⁺.
In order to write this formula correctly you MUST show:

• capital (or uppercase) N for the element nitrogen
• capital (or uppercase) H for the element hydrogen
• a subscript number 4 to indicate the presence of 4 hydrogen atoms in the molecule
• a superscript + sign to indicate that the molecule has a positive charge

When you answer a question at ausetute.com.au requiring a chemical formula, you will need to use the buttons on the textbox provided to make a subscript number and a superscript charge sign.

Here is a quick lesson in how to type your chemical formula into the textbox so that it displays the correct formula and not an incorrect formula (like NH4+)