A grain of sand is made up of 1.38 * 10-3 grams of oxygen and 0.00122 grams of silicon. What is the total weight, in grams, of the grain of sand?

2.6 * 10⁻³ g (Or) 0.0026 g

Data Given;

Mass of Oxygen = 1.38 * 10⁻³ g

Mass of Silicon = 0.00122 g = 1.22 * 10⁻³ g

Solution:

The total weight of grain of sand is calculated by adding the masses of Oxygen and Silicon as,

Total Weight = Mass of Oxygen + Mass of Silicon

Putting values,

Total Weight = 1.38 * 10⁻³ g + 1.22 * 10⁻³ g

Total weight = 2.6 * 10⁻³ g

Or,

Total weight = 0.0026 g