The number of electrons in the outermost shell determines essentially the type of chemical reactions that an atom participates in it is because these electrons are involved in chemical reactions as they can be donated, shared and thus rearranged by forming covalent bonds to produce new substances
yea you can scan a question
I think it is A . eubacteria
Answer: The different layers are a result of lighter parts (such as the continental crust) settling at the surface level and heavier parts (such as iron and nickel in the core) settling in the middle. The layers separate by density, otherwise known as compositional layering. The earth did not always have these layers, as it had to undergo cooling to form some of them (like the continental crust).
