What is the density of gold at 20 °C?

What is the density of gold at 20 °C?

• A. 18.0 g/cm³
• B. 20.0 g/cm³
• C. 19.3 g/cm³
• D. 21.0 g/cm³

Answer: (C)

Density is mass per unit volume, an intensive property that stays roughly constant for a pure substance at a given temperature. Gold is very dense because it has a large atomic mass and atoms are packed in a close-packed crystal structure. At room temperature, the density of gold is about 19.32 g/cm^3; rounding to one decimal place gives 19.3 g/cm^3, which is the value around 20 °C. Temperature changes around room temperature cause only a small expansion, so the density remains near this value. The other options are far from gold’s known density and don’t reflect how little density changes with small temperature shifts.

Density is mass per unit volume, an intensive property that stays roughly constant for a pure substance at a given temperature. Gold is very dense because it has a large atomic mass and atoms are packed in a close-packed crystal structure. At room temperature, the density of gold is about 19.32 g/cm^3; rounding to one decimal place gives 19.3 g/cm^3, which is the value around 20 °C. Temperature changes around room temperature cause only a small expansion, so the density remains near this value. The other options are far from gold’s known density and don’t reflect how little density changes with small temperature shifts.