If you need 100.0 mL of 0.450 M acidic H+ ions what mass of citric acid must be obtained?

How many moles of magnesium is 3.01 x10^22 atoms of magnesium?

Which process does not require the presence of a physical substance in order to transfer heat? air in the atmosphere is heated by the ground. this warm air then rises, and cooler air falls. this is an example of what type of process? how is conduction different from radiation?

Calculate the energy required to ionize a hydrogen atom to an excited state where the electron is initially in the n = 5 energy level. report your answer in kilojoules