Question

Suppose you have 3.00×1018 reams of lead (pb). how many lead atoms do you have? express the number of atoms numerically.

Answer 1

Answer : The number of atoms of lead are $1.5\times 10^{21}$

Explanation :

As we know that, 1 ream is equivalent to 500 atoms.

1 reams = 500 atoms

Now we have to determine the number of lead atoms.

As, 1 reams of lead = 500 atoms of lead

So, $3.00\times 10^{18}$ reams of lead = $3.00\times 10^{18}\times 500=1.5\times 10^{21}$ atoms of lead

Therefore, the number of atoms of lead are $1.5\times 10^{21}$

Answer 2

Reams are used to give large quantities. 
A ream is equivalent to 500 atoms.There are 3 x 10¹⁸ reams of Pb. 
Since 1 ream is equivalent to 500 atoms, 
Then 3 x 10¹⁸ reams of Pb contains - 500 x 3 x 10¹⁸ atoms
   = 1500 x 10¹⁸ atoms
Therefore total number of Pb atoms are - 1.5 x 10²¹ Pb atoms