Learn and try: Density (article) | Density | Khan Academy

Understanding Density

• Definition: Density is defined as the amount of mass contained within a given volume.
• Core Formula: Density = Mass / Volume ($\rho = m/V$).
• Intrinsic Property: Density is an intrinsic property, meaning it is independent of the total amount of the substance present.
• Temperature Effects: Density generally changes with temperature; substances are typically denser at lower temperatures and less dense at higher temperatures.
• Buoyancy:
  • Water has a density of $1.0\text{ g/cm}^3$.
  • Substances with a density greater than water sink; those with a density less than water float.
• Historical Context: The discovery of density is attributed to Archimedes (c. 250 BCE), who utilized the principle of water displacement to determine the volume of irregularly shaped objects, famously used to verify the purity of a gold crown.
• Practical Measurement:
  • For irregularly shaped objects, volume can be determined by measuring the amount of water displaced by the object.
  • Density is a fundamental characteristic used to identify materials and predict how they will interact with other substances.