is this correct:

iron is heated in the air , iron (II) oxide is formed.
2Fe+O2--> 2FeO

Correct formula for iron (II) oxide.

2 atoms of Fe on each side.
2 atoms of O on each side

so it balances. Looks OK.

Yes, the statement is correct. When iron is heated in the presence of air (which contains oxygen), it reacts with oxygen to form iron (II) oxide.

The balanced chemical equation for this reaction is:

2 Fe + O2 → 2 FeO

To determine if this reaction is correct, we need to balance the equation. Balancing the equation ensures that there is an equal number of atoms of each element on both sides of the equation.

Here's how we can balance the equation:

1. Count the number of atoms on each side of the equation:
Left side (reactants): 2 Fe, 2 O
Right side (products): 2 Fe, 1 O

2. Balance the oxygen atoms by adjusting the coefficient in front of FeO:
Now the equation becomes: 2 Fe + O2 → 2 FeO

3. Check if the number of iron atoms is balanced:
Left side (reactants): 2 Fe
Right side (products): 2 Fe

The number of iron atoms is already balanced, so we don't need to make any changes.

Therefore, the balanced equation is 2 Fe + O2 → 2 FeO, which represents the reaction where iron is heated in the air to form iron (II) oxide.