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Compound reference

Hydrogen peroxide

H₂O₂

HOOH
Geometry
bent
Bond angle
104°
Elements:HO

The chemistry

A chain: H–O–O–H. The two oxygens hold hands in the middle. Add heat and that O–O bond snaps - the basis of bleach.

Remember it as…

H–O–O–H. The middle bond is the weak link. Each O bent like in water, two lone pairs each.

Common mix-up

H₂O₂ is NOT "two waters stuck together." (H₂O)₂ would be two complete H–O–H units. H₂O₂ is one molecule with one continuous backbone - the two O atoms are bonded to each other.

Where the name comes from

Per- (Latin "very/through") + oxide. The "per-" prefix in chemistry signals an extra oxygen beyond the normal oxide.

Where you meet it

Antiseptic, hair bleach, rocket-fuel oxidizer - all uses of the same trick: that weak O–O bond breaks easily and releases reactive oxygen.

PubChem facts

IUPAC name
hydrogen peroxide
Molecular weight
34.015 g/mol

Also known as: hydrogen dioxide

Handling note

A strong oxidizer; concentrated solutions are corrosive and burn skin, though the dilute drugstore form is mild.

Verify on PubChem →

BondingMolecular geometry

Chemical data from PubChem (NIH/NCBI)