Chemical formulae are the universal language of chemistry — and once you can read them, a whole new level of understanding opens up. This video teaches you a step-by-step method for decoding any formula: counting elements, reading subscripts, and working through brackets, finishing with the Co versus CO example that shows why capitalisation can mean the difference between cobalt and carbon monoxide. The foundation you need before tackling formula masses and balanced equations.

What You Will Learn

00:42What a chemical formula is and why it is the universal language of chemistry.

01:49How to count capital letters in a formula to identify the number of different elements present.

04:29How to read subscript numbers and what they tell you about atom ratios.

04:43Why a subscript number always refers to the element immediately before it.

05:13How to handle brackets in formulae by multiplying the subscript outside the bracket by each atom inside.

05:29Why capitalisation in chemical symbols is critical: Co vs CO gives two completely different substances.

06:10How to look up unfamiliar element symbols using the periodic table.

07:43How to identify whether a substance is an element or a compound from its formula.

09:23How to apply all of these skills together to fully decode a complex formula.

There's more than one way to write a chemical formula, and knowing which to use — and why — matters in exams. This video explains the difference between empirical, molecular, structural, and displayed formulae with clear examples showing when each applies. By the end you'll be able to identify the formula type you're looking at and convert between them with confidence.

What You Will Learn

01:19There is more than one way to write a chemical formula, and knowing which to use — and why — matters in exams.

01:42What an empirical formula shows and why it gives the simplest whole-number ratio of elements.

03:39What a molecular formula shows and when it is more useful than an empirical formula.

04:00What a condensed structural formula shows and how it differs from a molecular formula.

05:01How to read a displayed formula where every bond and every atom is shown explicitly.

07:32What a skeletal formula is and how to interpret the line-angle notation used in organic chemistry.

09:03How ionic and covalent compounds differ in the type of formula that best represents their structure.