(Science) Determine the number of atoms of each element that makes the following compound: CaCl2. Be sure to select zero if an element is not present in the compound. Carbon:___ Calcium: Chloride:Hydrogen: Oxygen:

Which two molecules do green plants use to make glucose? o a. nitrogen and water o b. hydrogen and oxygen o c. carbon dioxide and water o d. methane and iron oxide

Molecular models of two different substances are shown below. in the molecule on the left, the oxygen atom pulls on electrons more strongly than the hydrogen atoms. in the molecule on the right, the two oxygen atoms pull on the shared electrons with the same strength. water molecule, h,o oxygen molecule, oz when the two substances are put in the same container, they do not attract each other. why does this happen? a. they both contain oxygen. b. one is polar and one is nonpolar. c . they are both polar. d. they contain different elements.

What substance acts to prevent sudden ph changes in bodily fluids?