`3.011 xx 10^22` atoms of an element weighs `1.15 gm`. The atomic mass of the element is :

Options

A. 23
B. 10
C. 16
D. `35.5`

Answer

A

Explanation

From Avogadro's law
`6.023 xx 10^(23)` atoms or Avogadro,s number of an
element contains mass = Atomic mass of the element
`because 3. 011 xx 10^(23)` atoms of an element weight `1.15` g
`therefore 6.023xx 10^(23)` atoms of an element will weight
`= (1.15xx 6.023xx10^(23))/(3.011xx10^(23))=23`
Hence, atomic mass of the element is 23.