Fluids are amounts of matter composed of molecules and atoms weakly bonded together.

Examples: a rock, a table, a knife, a block of ice.

Solids are material objects made up of molecules and atoms so strongly bonded together that they tend to keep their shape even when moved around, though they can deform under stress.

Physicists also classify matter in a few broad categories, called states, with quite different properties:

Each atom, in turn, is an assemblage of elementary particles. A molecule is formed when two or more atoms join together chemically. Cells are composed of molecules, which are sets of atoms bonded together.

Hence, living organisms are made up of cells.

The structure and composition of matter is investigated by breaking matter into smaller and smaller pieces. Just for example, emotions can be experienced or ideas can be had. Outside of the physical sciences, there can be many other things that aren't matter or energy. In addition to its rest mass, matter can contain other forms of energy, which aren't matter but allow them to interact with each other by exchanging kinetic energy, heat, light, sound waves, etc. Photons (electromagnetic radiation such as light) are a familiar example. In physics, the universe also contains things that aren't matter, including some elementary particles that have no rest mass. Living organisms like plants, animals and humans are also composed of matter. Examples of matterĪll physical bodies in the universe are made of matter: galaxies, stars and planets, rocks, water and air. It has properties which can be measured, such as mass, volume, density, and qualitative properties such as taste, smell and colour, for instance. Matter can be directly experienced through the senses. The process by which baryons came to outnumber their antiparticles is called baryogenesis. It is assumed that the Big Bang produced a state with equal amounts of baryons and antibaryons. The very existence of baryons is a significant issue in cosmology.

What is matter made of