Matter is everything around us that has mass and takes up space. It exists in different forms and can be classified based on its unique properties.

States of matter definition and examples include the three main forms that substances can take: solids, liquids, and gases. In solids, particles are tightly packed and have a fixed shape, like a wooden desk or a metal spoon. Liquids have particles that can flow and take the shape of their container while maintaining a constant volume, such as water or milk. Gases have particles that move freely and spread out to fill any container completely, like the air we breathe or helium in a balloon.

The classification of matter and its properties helps us understand how different substances behave. Physical properties include characteristics we can observe without changing the substance's chemical makeup, such as color, texture, density, and melting point. Chemical properties describe how a substance reacts with other materials, like how iron rusts when exposed to air and moisture. One important concept to understand is the difference between mass and weight in physics - mass measures the amount of matter in an object and stays constant everywhere, while weight is the force of gravity acting on that mass and can change depending on location. For example, an astronaut's mass remains the same on Earth and the Moon, but their weight would be less on the Moon due to lower gravity. Understanding these fundamental concepts helps us make sense of how matter behaves in our everyday lives and in different environments.