I believe it would be the first option. It forms iron oxide (rust) when exposed to moisture and air.
Natural selection requires variation between individuals. Mutations and reproduction increase genetic variation in a population. Natural selection occurs when environmental pressures favor certain traits that are passed on to offspring.
Answer: Two possible ways to show the structure of CH4 are its electron dot diagram or structural formula. CH4 or methane's molecular formula is given as CH4. The structural formula is a graphical representation of a chemical compound.
