#### Answer

$40$ $Earth-circumferences$

#### Work Step by Step

Using unit conversions, we find:
$\frac{1.5 \times 10^{-10}m}{1-atom} \times 10^{19} atoms \times \frac{1km}{1000m} \times \frac{1-Earth-circumference}{40075 km} =$
$40$ $Earth-circumferences$