Which substance is not one of the common elements of organic compounds? a. hydrogen b. helium c. nitrogen d. phosphorus

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

What is the ph of a solution that has a hydrogen ion concentration of 1.0 * 10 -9 m?

If 16.00g of hydrogen gas reacts with 126.73g of oxygen, how many grams of water are yielded? (both reactants are completely consumed in the reaction.)