Answer:
4Fe + 3O₂ → 2Fe₂O₃
Explanation:
Fe → ²⁺
O → ²⁻
But Iron III is Fe³⁺
So we have Fe³⁺ and O²⁻, the formula for the oxide must be Fe₂O₃ so the equation can be:
4Fe + 3O₂ → 2Fe₂O₃
The troposphere protect the molecules because there are higher layers on top. This makes life possible on Earth.
The appropriate answer is a. it involves a change in the molecular structure of the substance. A change in phase or state is referred to as a physical change. For example...liquid water freezing is a physical change because the state changes but solid water is still H20. Separating water into its constituent atoms, hydrogen and oxygen is a chemical change because the molecular structure of water is now non existent.
Jeez this is middle school really. covalently bond