For one mole of any element, there is always 6.022 x 10^23 atoms. The figure is called the Avogadro's number. In this case, we are given with 0.0845 moles of tungsten, to determine the number of atoms, we multiply 0.0845 moles by 6.022 x10^23 atoms. The answer is 5.08859 x 10^22 atoms.