If each vitamin has 0.8  grams of calcium, how much calcium will 2.6 vitamins have?

If the atomic mass of an atom is 34 and the atom contains 13 protons, how many neutrons does the atom contain?

What stress will shift the following equilibrium system to the left? n2(g) + 3h2(g) ⇌ 2nh3(g) adding more n2(g) adding more nh3(g) increasing the pressure of the system reducing the volume of the container

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