In 1928, 47.5 g of a new element was isolated from 660 kg of the ore molybdenite. the percent by mass of this element in the ore was:

The mass percent of element in the ore is 0.0072 %

Explanation:

To calculate the mass percentage of element in ore, we use the equation:

Mass of element = 47.5 g

Mass of ore = 660 kg = 660000 g    (Conversion factor:  1 kg = 1000 g)

Putting values in above equation, we get:

Hence, the mass percent of element in the ore is 0.0072 %

1. they vary with a higher number because boiling is way hotter than melting