Explain why coal, oil, and natural gas are fossil fuels.

They are fossil fuels because they were formed because of fossilized remains of animals and plants that lived many years ago. They also have a high carbon content.

sodium (na), for example, has one electron in its valence shell. this is an unstable state because that valence shell needs eight electrons to be full. in order to fill its valence shell, find a way to add seven electrons to its valence shell