According to the laws of physics, everything in the universe has mass. Mass is a fundamental property of matter and is defined as the amount of matter an object contains. Even the smallest particles, such as electrons, have a mass.
In classical physics, it was believed that mass was an inherent property of all objects and therefore, nothing could have no mass. However, in modern physics, massless particles such as photons and gluons have been discovered. These particles do not have a rest mass, but they still have energy and momentum.
Mass and weight are often used interchangeably, but they are not the same thing. Mass is a measure of the amount of matter an object contains, while weight is a measure of the force of gravity acting on an object. Mass remains the same regardless of location, but weight can change depending on the strength of gravity.
No, mass and density are not the same. Density is the measure of how tightly packed the matter in an object is, while mass is the measure of the amount of matter. Objects with the same mass can have different densities, depending on their size and composition.
Mass is typically measured using a balance or a scale. In scientific experiments, mass is commonly measured in kilograms (kg), while in everyday life, it is measured in grams (g) or pounds (lbs). The standard unit of mass in the International System of Units (SI) is the kilogram, defined as the mass of a specific platinum-iridium alloy cylinder kept at the International Bureau of Weights and Measures in France.