Physical Measurements and SI Units

Physical Quantities

• Physical quantities are characteristics of matter that can be observed without changing the chemical makeup of a substance.
• Examples of physical quantities include length, mass, color, and scent.

International System of Units (SI)

• The SI is an international system of measurements of physical quantities that originated from the metric system.
• The SI was developed when scientists worldwide agreed to use a common system for scientific work.
• The SI is the most widely used system of measurement, especially in scientific work.
• The abbreviation "SI" is based on the system's French name, Système Internationale d'Unités.

SI Base Units or Basic Quantities

• The SI consists of seven base units or basic quantities, from which other units are derived.
• The seven base units of the SI are:
  • Metre (m) - used to measure length and distance
  • Kilogram (kg) - used to measure mass, equal to 1,000 grams
  • Second (s) - used to measure time
  • Kelvin (K) - used to measure temperature
  • Ampere (A) - used to measure electrical current
  • Candela (Cd) - used to measure luminous intensity or brightness
  • Mole (mol) - used to measure the amount of substance

Physical Quantities

• Physical quantities are characteristics of matter that can be observed without changing the chemical makeup of a substance.
• Examples of physical quantities include length, mass, color, and scent.

International System of Units (SI)

• The SI is an international system of measurements of physical quantities that originated from the metric system.
• The SI was developed when scientists worldwide agreed to use a common system for scientific work.
• The SI is the most widely used system of measurement, especially in scientific work.
• The abbreviation "SI" is based on the system's French name, Système Internationale d'Unités.

SI Base Units or Basic Quantities

• The SI consists of seven base units or basic quantities, from which other units are derived.
• The seven base units of the SI are:
  • Metre (m) - used to measure length and distance
  • Kilogram (kg) - used to measure mass, equal to 1,000 grams
  • Second (s) - used to measure time
  • Kelvin (K) - used to measure temperature
  • Ampere (A) - used to measure electrical current
  • Candela (Cd) - used to measure luminous intensity or brightness
  • Mole (mol) - used to measure the amount of substance