What is not a matter?
Things That Are Not Matter
Time. Sound. Sunlight. Rainbow. Love.
Matter is usually defined as something that has mass and takes up space. So a shadow is not matter, since it has no mass and takes up no space. Instead, a shadow is a lack of light on a certain area.
The seven states of matter that I am investigating are Solids, Liquids, Gases, Ionized Plasma, Quark-Gluon Plasma, Bose-Einstein Condensate and Fermionic Condensate. Solid Definition - Chemistry Glossary Definition of Solid.
Light exists in tiny packets called photons. Photons have no rest mass and they do not occupy any volume. So light is not matter.
States of Matter
Not only is water the most common substance on earth, but it is also the only substance that commonly appears as a solid, a liquid, and a gas within the normal range of earth's temperatures. This makes water a good model for discussing the solid, liquid, and gas states of matter.
But what we can conclude (for now) is that, of the fundamental states of matter, fire is most like a plasma. In fact, some very hot flames do contain plasma – when the energy inside them is sufficient to ionise enough of the air molecules.
But, like solids and liquids, air is matter. It has weight (more than we might imagine), it takes up space, and it is composed of particles too small and too spread apart to see.
Whereas sound is also not considered a matter as it does not occupy space.
Wind is the air in motion, and air is a matter which occupies space and have mass also, but wind is an effect or motion in the matter so it is a phenomenon which could not be a matter but the air particles moving in the wind is a matter.
Matter is something that has volume (takes up space) and has mass (*can be weighed). Air does take up space, even if we can't see it, and air has weight, even if we can't feel it -- and both of these properties can be observed and measured.
Are shadows dark matter?
Your original question asked if dark matter could be shadows. The answer is no.
Light is not made out of atoms or anything like them. Electromagnetic waves are themselves a basic ingredient of our world. It's the light itself which enters our eyes. It is absorbed by special molecules which change their chemical configuration as a result of that absorbed energy.

Why Doesn't Light Have Mass? - YouTube
Phase | Shape | Density |
---|---|---|
Gas | fills entire container | low |
Liquid | fills a container from bottom to top | high |
Solid | rigid | high |
The answer is that there are four fundamental states of matter – solid, liquid, gas and plasma. These are the ones that occur naturally in the Universe.
The sun is made up of a blazing combination of gases. These gases are actually in the form of plasma. Plasma is a state of matter similar to gas, but with most of the particles ionized.
Space and time don't exist without matter, they exist only related with matter. Therefore space and time are not quantities, but qualities of reality.
Smoke, smog, and laughing gas are matter. Energy, light, and sound, however, are not matter; ideas and emotions are also not matter.
Rain is a liquid. The liquid state is a state of matter which has no definite shape like gases.
Water illustrates the three states of matter: solid (ice), gas (steam), and liquid (water). The form it takes depends upon the temperature.
Is Lemon a matter?
Yes, it is matter.
What Are Clouds Made Of? - YouTube
Electricity is not matter because electricity is the movement of matter.
fog is matter: it consists of tiny droplets of liquid water (which is matter) mixed into the gaseous air (which is also matter).
Because it has no mass or occupies no space, cold is not a substance. It's merely a sensation. Cold drink, on the other hand, is a liquid with mass and space, hence it is matter. A cold drink is essentially a liquid with mass and volume.
Air and smell of perfume are gaseous states of matter. Note: The sense of smell is not matter. However, the smell or odour of a substance is Classified as matter.
Heat is a form of energy, and energy is not a form of matter because it is not composed of atoms or molecules.
Non-matter includes the light from a torch, the heat from a fire, and the sound of a police siren. You cannot hold, taste, or smell these things. They are not types of matter, but forms of energy. Everything that exists can be classed as either a type of matter or a form of energy.
But, like solids and liquids, air is matter. It has weight (more than we might imagine), it takes up space, and it is composed of particles too small and too spread apart to see.
Whereas sound is also not considered a matter as it does not occupy space.
Is fire a matter?
But what we can conclude (for now) is that, of the fundamental states of matter, fire is most like a plasma. In fact, some very hot flames do contain plasma – when the energy inside them is sufficient to ionise enough of the air molecules.
Wind is the air in motion, and air is a matter which occupies space and have mass also, but wind is an effect or motion in the matter so it is a phenomenon which could not be a matter but the air particles moving in the wind is a matter.
On earth, solid, liquid, and gas are the most common states of matter. Not only is water the most common substance on earth, but it is also the only substance that commonly appears as a solid, a liquid, and a gas within the normal range of earth's temperatures.
Smoke is made up of a complex mixture of gases and fine particles produced when wood and other organic matter burn. A major health threat from smoke comes from fine particles (also called particle pollution, particulate matter, or PM).
The sun is made up of a blazing combination of gases. These gases are actually in the form of plasma. Plasma is a state of matter similar to gas, but with most of the particles ionized.
Because it has no mass or occupies no space, cold is not a substance. It's merely a sensation. Cold drink, on the other hand, is a liquid with mass and space, hence it is matter. A cold drink is essentially a liquid with mass and volume.
Air and smell of perfume are gaseous states of matter. Note: The sense of smell is not matter. However, the smell or odour of a substance is Classified as matter.
No, sunlight is not a matter because it does not occupy space. Sunlight is a form of electromagnetic radiation and is made of small particles called photons. Photons do not have mass and have very high speed.
Matter is anything that has mass and occupies space. Sugar has mass and it occupies space, so it is a matter.
Space and time don't exist without matter, they exist only related with matter. Therefore space and time are not quantities, but qualities of reality.
Is ice a matter?
Water illustrates the three states of matter: solid (ice), gas (steam), and liquid (water). The form it takes depends upon the temperature. At low temperatures, the molecules do not move around as much and form a crystalline structure that is rigid (ice).
What Are Clouds Made Of? - YouTube
Water, like all other types of matter, requires the addition or removal of energy to change states. A block of ice is solid water. When heat (a form of energy) is added, the ice melts into liquid water.