Question

Determine the number of atoms in each of the following quantities of an element.

a. 10.0 g B
b. 32.0 g Ca
c. 2.0 g Ne
d. 7.0 g N​

Answer 1

Answer:

we know

no. of atoms = no.of moles× 6.022 ×10^23

a) no.of atoms of B= no.of moles of boron ×6.022×10^23

no.of moles = given mass of boron/molecular mass of boron

no.of moles =10/11

no.of atoms of boron=10/11×6.022×10^23

=5.47×10^23 atoms

b) no.of atoms of ca =32/40×6.022×10^23=4.8×10^23

c)no.of atoms of Ne=2/20×6.022×10^23=0.6022×10^23

=6.022×10^22

d)no.of atoms of N=7/14×6.022×10^23

=3.011×10^23 atoms