Quick self-quiz

Tap each word to check what it stands for.

When to use it

Use it when writing chemical equations to remember which seven elements must be written as diatomic molecules rather than single atoms.

Example

The combustion of hydrogen is written 2H2+O22H2O2\text{H}_2 + \text{O}_2 \to 2\text{H}_2\text{O}, not 2H+O2\text{H} + \text{O}, because both are diatomic.

Common mistake

Forgetting chlorine, which starts with Cl, not C. The C in the phrase stands for chlorine, not carbon.