There are 1.677 x 10²⁷ Cu atoms.
Solution:
177 kg Cu * (1000g / 1kg) * (1 mol / 63.546 g) * (6.022 x 10²³ atoms Cu / 1 mole) = 1.677 x 10²⁷
Chemists can measure a quantity of matter using mass, but in chemical reactions it is often important to consider the number of atoms of each element present in each sample. Even the smallest quantity of a substance will contain billions of atoms, so chemists generally use the mole as the unit for the amount of substance.
One mole (abbreviated mol) is equal to the number of atoms in 12 grams of carbon-12; this number is referred to as Avogadro's number and has been measured as approximately 6.022 x 10²³. In other words, a mole is the amount of substance that contains as many entities (atoms, or other particles) as there are atoms in 12 grams of pure carbon-12.
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