* Atoms vs. Moles: A mole is a unit of measurement that represents a specific number of particles (6.022 x 10^23 particles, also known as Avogadro's number). So, 1 mole of hydrogen atoms contains 6.022 x 10^23 hydrogen atoms.
* Atomic Mass: Hydrogen and helium have different atomic masses. Hydrogen has an atomic mass of approximately 1 atomic mass unit (amu), while helium has an atomic mass of approximately 4 amu. This means that a helium atom is about four times heavier than a hydrogen atom.
Therefore:
* 1 mole of hydrogen atoms weighs 1 gram.
* 1 mole of helium atoms weighs 4 grams.
Even though they contain the same number of particles (6.022 x 10^23), the two samples will have different masses because the individual atoms have different masses.
