Physical Science


To measure, to assign a number to an object that can be compared with other objects. Unit of measurement depends on what we are measuring.

State of matter

A state of matter is one of the distinct forms that matter exists in.There are five states of matter: solids, liquids, gases, plasma and Bose-Einstein condensates.


A measure of the quantity of mass of an object per unit volume. Mass divided by volume.


Heat is a form of energy that is transferred between two substances that have different temperatures. Heat flows from the substance of higher temperature to the substance of lower temperature.


An element is a pure substance that cannot be broken down into further simpler components. Elements consist of only one type of atom that are specific to that element only. Learn about the Periodic Table.


An atom is the smallest particle of an element. All Atoms of a specific element have the same properties as chemical makeup, size, and mass.


Chemical bond is the attraction that holds atoms together to form a compound. Some examples are ionic bonds and covalent bonds.

Mixture, Compounds, Elements

Mixtures are made of two or more different elements and/or compounds, that are not chemically bound together. Atoms from two or more different elements bind together into a molecule.

Physical and Chemical Change

A physical change does not really change the substance. However, a chemical change during a chemical reaction results in a new substance being formed.


Motion is the act of moving. It involves speed, velocity, acceleration, etc. Learn Newton’s three laws of motion.


Force is any kind of push or pull on an object when that object is interacting with another object.


Energy is the ability to do work. Examples are potential, kinetic, thermal, electrical, and nuclear.