Oxygen
Syre
ChemistryCommon
Discovered 1772 · C. W. Scheele
SPARKON07 / 10
Oxygen
The ideaOxygen has 6 outer electrons and wants 2 more, so it reacts with almost everything.
O · atomic number 8 · shells 2, 6
Lets you predictIt forms O²⁻ ions and two bonds.
Tests usually ask
- Electron shells and ions
- Burning = reacting with oxygen
Scan for the full explanation and a practice question.
SPARKON · 07 / 10
SPARKON · 07 / 10
Flip the card (click, tap, or Enter / Space)
Chemistry ● Common: a core idea every course needs
Oxygen
Oxygen has 6 outer electrons and wants 2 more, so it reacts with almost everything.
O · atomic number 8 · shells 2, 6
Why it works
Common card because oxygen is common: it is about a fifth of the air and almost half of the mass of Earth's crust, locked into rock and water.
Scheele found it in his pharmacy lab in Sweden, but his book came out late, so Priestley in England often gets the credit.
What it lets you predict
It forms O²⁻ ions and two bonds.
How tests ask about it
- Electron shells and ions
- Burning = reacting with oxygen
Try it
How many electrons does an oxygen atom need to fill its outer shell, and what ion does it form?
Show the answer
It has 6 outer electrons and needs 2 more, so it forms O²⁻.
Connects to
Wins these Lab Duel challenges
- Why does ice float on a lake? see challenge