Final answer:
The gram is the basic unit to measure weight in the metric system, with the kilogram being more commonly used as the standard unit of mass in the SI system.
Step-by-step explanation:
The basic unit used to measure weight in the metric system is the gram (g). The kilogram (kg), which is equal to 1,000 grams, is commonly used as a standard unit of mass in the International System of Units (SI). While weight and mass are often used interchangeably in everyday language, in scientific terms, weight refers to the force that gravity exerts on an object, which is dependent on both its mass and the acceleration due to gravity. Mass, on the other hand, is a measure of how much matter an object contains and does not change regardless of location. A gram is defined as ¹⁄₁₀₀₀ of the mass of the kilogram, which is about 2.2 pounds.