[tex]1mol...39g \: potasiu...6.022 \times {10}^{23 \:} atomi \: potasiu \\ ...........x \: g \: potasiu...12.046 \times {10}^{23} atomi \: potasiu[/tex]
[tex]x = \frac{39 \times 12.046 \times {10}^{23} }{6.022 \times {10}^{23} } = 78.012 \: g \: potasiu[/tex]
