Matter and its Composition
Matter has mass, occupies space and can be perceived by the physical senses.
Solid, liquid and gas are the three states of matter.
Heat, sound, magnetism, happiness and shadow are not regarded as matter because neither they have mass nor they occupy space.
Matter is made up of extremely small particles called atoms or molecules. Atom is the smallest unit of matter which cannot be broken further. Molecule is the smallest particle of matter that can exist independently.
Particles of matter have inter particular or intermolecular spaces between them. The particles are held together by intermolecular forces of attraction.
Particles of matter are always in random motion.
One state of matter can be converted into another by changing the conditions of temperature and pressure.