What is the mass of a liter of water?

Water has a well-known density of approximately 1 kilogram per liter at standard temperature and pressure. This relationship is fundamental in various scientific and practical applications, such as cooking measurement, laboratory work, and understanding buoyancy. Therefore, when considering the mass of a liter of water, it directly correlates to its density. Since 1 liter of water has a mass of 1 kilogram, this makes the correct answer clear as it aligns perfectly with the established density of water. Understanding this principle is crucial for anyone entering trades or fields that involve measurements of liquids and their properties.