Question

Which equation is balanced?
Responses

4H2+ O2→H2O + ​O
4 uppercase H subscript 2 end subscript plus uppercase O subscript 2 end subscript rightwards arrow uppercase H subscript 2 end subscript uppercase O plus uppercase O

2H2+ O2→2H2O
2 uppercase H subscript 2 end subscript plus uppercase O subscript 2 end subscript rightwards arrow 2 uppercase H subscript 2 end subscript uppercase O

H2+ O2→H2O + O2
uppercase H subscript 2 end subscript plus uppercase O subscript 2 end subscript rightwards arrow uppercase H subscript 2 end subscript uppercase O plus uppercase O subscript 2 end subscript

H2+ O2→H2O
uppercase H subscript 2 end subscript plus uppercase O subscript 2 end subscript rightwards arrow uppercase H subscript 2 end subscript uppercase O

Answer 1

The balanced equation is:
2H2 + O2 → 2H2O

Check by counting atoms:
- Left: H = 2×2 = 4, O = 2
- Right: H = 2×2 = 4, O = 2×1 = 2

All atoms balance.