Question

which equation is balanced?
mg + 2o₂ → 2mgo
al + 3o₂ → al₂o₃
na + f₂ → 2naf
2al + 3f₂ → 2alf₃

Explanation:

Step1: Check Mg + 2O₂ → 2MgO

• Mg atoms: 1 on left, 2 on right.
• O atoms: 4 on left, 2 on right.

Step2: Check Al + 3O₂ → Al₂O₃

• Al atoms: 1 on left, 2 on right.
• O atoms: 6 on left, 3 on right.

Step3: Check Na + F₂ → 2NaF

• Na atoms: 1 on left, 2 on right.
• F atoms: 2 on left, 2 on right.

Step4: Check 2Al + 3F₂ → 2AlF₃

• Al atoms: 2 on left, 2 on right.
• F atoms: 6 on left, 6 on right.

Answer:

2Al + 3F₂ → 2AlF₃