Science: Physical quantites and units

Hi guys, today I will be posting about physical quantities and SI units.

You must be wondering, what is a physical quantity?

Well, "A physical quantity (or "physical magnitude") is a physical property of a phenomenon body, or substance, that can be quantified by measurement".

"Most physical quantities include a unit, but not all - some are dimensionless. Neither the name of a physical quantity, nor the symbol used to denote it, implies a particular choice of unit, though SI units are usually preferred and assumed today due to their ease of use and all-round applicability. For example, a quantity of mass might be represented by the symbol m, and could be expressed in the units kilograms (kg), pounds (lb), or daltons (Da)."

These are the base quantities:

What are SI units?

"The International System of Units (abbreviated SI from French: Le Système international d'unités) is the modern form of the metric system and is the world's most widely used system of measurement, used in both everyday commerce and science. It comprises a coherent system of units of measurement built around seven base units, 22 named and an indeterminate number of unnamed coherent derived units, and a set of prefixes that act as decimal-based multipliers."

Here are some prefixes: