Symbol equations are a quick way of representing chemical reactions. They show us what atoms are involved and how they are bonded together. Symbol equations always take the form, reactants → products.

"Even the +, −, =, and x signs we take for granted only came into widespread use in the 17th century. Which means that the earlier algebraists we know of … all had expressed their equations mostly in ...

For example, when heated, green copper(II) carbonate decomposes into black copper(II) oxide and colourless carbon dioxide gas. Nitrogen and hydrogen react together to form ammonia. Give the word ...