Calcium oxide (cao) forms when an atom of calcium loses two electrons, giving it a +2 charge and an atom of oxygen picks up two electrons, giving it a -2 charge. what is calcium oxide? a- an element b- a covalently bonded compound c- an ionically bonded compound

Easy definition for atom and atomic mass

Choose all the answers that apply. ionic compounds dissolve easily in water do not dissolve in water have low melting points have high melting points conduct electricity when melted

Although respiratory organs vary across different organisms, they all contain respiratory surfaces that have a large surface area and are extremely thin. explain why having an extremely thin respiratory surface with a large surface area is advantageous for the process of gas exchange