  Crushed stone, for example, has a density of 100 pounds per cubic foot (lb/ft3), which is 1600 kilograms per cubic meter (kg/m3), which is 1.6 metric tons per cubic meter. Packed earth is about 95 lb/ft3, or 1520 kg/m3.
Harvard Business Review. Harvard Business Review. The Harvard Business Review (HBR) is a general management magazine published by Harvard Business Publishing, a wholly owned subsidiary of Harvard University. It is published 6 times a year and is headquartered in Brighton, Massachusetts.
Hydrogen bromide is the diatomic molecule with the formula H Br. HBr is a colorless gas that condenses to a colorless liquid. Hydrobromic acid is a solution of HBr in water. Hydrogen bromide and hydrobromic acid are, therefore, not the same, but they are related. Commonly, chemists refer to hydrobromic acid as HBr, and this usage, while understood by most chemists, is imprecise and can be confusing to the non-specialist.