What is the reason why the identification of bacteria normally requires more than simply examination under a light microscope

The table below shows the elements that mainly comprise each of the four layers of earth: elements in layers layer main elements crust oxygen, silicon mantle iron, magnesium outer core iron, nickel inner core iron which of these elements make up the layer that is 0.2 to 1.1 percent of earth's total diameter?

Which three statements represent the benefits of performing experiments using computer simulations?

When sodium chloride dissolves in water the sodium cholride dissociates into?