Chemistry · KS3 Y7 · Atoms, Elements & Compounds

Chemical symbols

Chemical symbolsFree2:17Heddy Score 3 of 7, below the standard
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What you need to know

  • The number of protons in an atom decides which element it is, and this is the atomic number shown on the periodic table.
  • Each element has a one- or two-letter symbol, such as C for carbon and Li for lithium, with a capital first letter.
  • Some symbols come from older names and are not obvious, such as Na for sodium and Fe for iron.
  • If a symbol is unfamiliar, the periodic table lists both the symbol and the name so it can be checked.

In this clip

Runs 2:17, from 0:06 to 2:23 of the full video.

Heddy Score3/7, Below the standard
See the seven stars
  • Trusted source · passed. The creator's own upload, live and playable here.
  • On the map · not judged yet. A teacher watched it: it mainly teaches this map topic.
  • Spec-true · not judged yet. Accurate, and right for the current UK specification.
  • Focused · passed. One idea, short enough to watch in one go.
  • Accessible · passed. Good captions, clear sound and pictures.
  • Safe for children · not judged yet. Right for 11 to 16 year olds, with no sales pitch.
  • Proven · not judged yet. Earned from our students: they learn from it, find it helpful and watch it to the end.
★ passed · ☆ pending · ✕ failed
Our students

Not enough students yet

Our own students' answers. These are what move ★7 Proven.
On YouTube

327K views · 3.75K likes · Cognito 1.37M subscribers

As reported by YouTube on 2026-11-02. Not part of the Heddy Score.
How the Heddy Score works

Why we picked it

A clear GCSE-level opening that links atomic number to element identity and shows how element symbols are read from the periodic table.

Cognito on YouTubechecked 2026-10-22

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