From Citizendium, the Citizens' Compendium
- Chemistry : The science of matter, or of the electrical or electrostatical interactions of matter.
- Physics : The study of forces and energies in space and time.
- Matter : Please do not use this term in your topic list, because there is no single article for it. Please substitute a more precise term. See Matter (disambiguation) for a list of available, more precise, topics. Please add a new usage if needed.
- Matter (chemistry) : In general chemistry, from the perspective of Newtonian mechanics, anything that occupies space and has mass.
- Atomic mass : The mass of an atom expressed in unified atomic mass units (u) and formerly known as atomic weight.
- Chemical elements : In one sense, refers to species or types of atoms, each species/type distinguished by the number of protons in the nuclei of the atoms belonging to the species/type, each species/type having a unique number of nuclear protons; in another sense, refers to substances, or pieces of matter, each composed of multiple atoms solely of a single species/type.
- Density (chemistry) : A measure of the mass per unit volume of a gas, liquid or solid.
- Force : Vector quantity that tends to produce an acceleration of a body in the direction of its application.
- International System of Units : Metric unit system based on the metre, kilogram, second, ampere, kelvin, mole and candela.
- Kilogram : The kilogram is the basic unit of mass in the International System of Units (SI, metric system).
- Kilogram-force : A unit of force which will accelerate 1 kilogram of mass to 9.80665 m/s2, the standard average acceleration due to gravity on Earth's surface (referred to as gn).
- Laws of conservation : The laws of science which state that a particular measurable property (or quantity) of an isolated physical system does not change (i.e., is constant) during the course of time.
- Pound (mass) : A measurement unit of mass used in the United States customary, Imperial, and other systems of measurement.
- Pound-force : A measurement unit of force which will accelerate 1 pound of mass to 9.80665 m/s2 (≈ 32.17405 ft/s2), the standard average acceleration due to gravity on Earth's surface (referred to as gn).
- U.S. customary units : The units of measurement that are currently used in the United States.
- Weight : The force with which a body is attracted to Earth or another celestial body, equal to the product of the object's mass and the acceleration of gravity.