Answer : The element is, Arsenic (As)
Solution : Given,
Mass of a pure element = 4.17 g
Number of atoms = [tex]3.35\times 10^{22}[/tex]
First we have to calculate the moles of a pure element.
[tex]\text{Number of moles of an element}=\frac{\text{Given atoms of an element}}{\text{Avogadro's number}}=\frac{3.35\times 10^{22}}{6.022\times 10^{23}}=0.0556moles[/tex]
Now we have to calculate the molar mass of an element.
Formula used :
[tex]\text{Moles of an element}=\frac{\text{Mass of an element}}{\text{Molar mass of an element}}[/tex]
Now put all the given values in this formula, we get
[tex]0.0556mole=\frac{4.17g}{\text{Molar mass of an element}}[/tex]
[tex]\text{Molar mass of an element}=75g/mole[/tex]
Thus, the arsenic is the element which has molar mass 75 g/mole.
Hence, the element is, Arsenic (As)
