Calculate the total moles of ions in 30.4 g FeBr₃.

Calculate the mass (g) of a sample containing 8.45 x 10²³ molecules of melatonin (C₁₃H₁₆N₂O₂).

A metal cube made out of pure iron has a side length of 3.50 cm. Iron has a density of 7.874 g/cm³ at room temperature. Calculate the number of iron atoms in the cube.

Constantan is a copper-nickel alloy containing 55.0 % copper and 45.0 % nickel. The density of the alloy is 8.885 g/cm³. A sphere made from constantan has a volume of 58.5 cm³. Calculate the number of copper and nickel atoms in the sphere.

Calculate the number of P atoms in 2.63 g of phosphorus pentabromide (PBr₅)

Calculate the mass in grams of Br 3.28 x 10²¹ molecules of PBr₅