Question #0de15

1 Answer
Apr 15, 2016

#A_r=58.99#

Explanation:

The number of moles of a substance is given by:
#(mass (grams))/("Relative atomic mass", A_r)#

And one mole comprises (Avogadro's constant), #N_A =6.022 times 10^23# atoms / molecules.

So number of atoms is given by:
#(mass (grams)*N_A)/("Relative atomic mass", A_r)#

In this case

# ((16.26times 10^-3g)/A_r)*(6.022 times 10^23)=1.66 times 10^20#

Rearranging gives:

#A_r= (16.26times 10^-3g)*(6.022 times 10^23)/(1.66 times 10^20)#
so
#A_r=58.99#