For 1 mole of any substance, there are 6.02214086 × 10^23 particles (atoms, molecules, ions, etc. depending on the substance)
So, for 1 mole of water, there are 6.02214086 × 10^23 water particles, and so on
So, in 1 mole of Lithium, there are 6.02214086 × 10^23 Lithium atoms