Strictly (though this is another thing about which usage can be loose) a mole is an amount of substance, not a number of things. A mole is that amount of substance that contains Avogadro's number NA of basic units (atoms, molecules, ions etc. as appropriate). 1 mole of potassium contains NA K atoms; 1 mole of potassium chloride contains NA K+ ions and NA Cl- ions. 1 mole of hydrogen gas contains NA H2 molecules, and therefore 2NA H atoms.