passage 1.
every material you encounter in your daily life is solid, liquid or gas.these are known as the three states of matter. there is a fourth state known as plasma, bu this can only existat extremely high temperatures, and is there for excerdingly rare on earth.
what defines a substance as a sokid liquid or gas may seem obvious at first but when you think about substances like toothpaste, margarine or jelly, their states are not as obvious. for something to be classed as a solid, it has to have a fixed volume and a fixed shape. solids are not easily compressed and do not flow, liquids also have a fixed volume but do not have a fixed shape. they take the shape of their container from the bottom up ward if they are inside one, and they flow when are poured our, like sokids, liquids are not easily compressed. which is why they are used in hydraulie brakes,
gases, on the other hand are highly compressible, they have no fixed shape. no fixed volume , and they flow eassily, taking up all the available space they can , every nook and cranny in your house is filled with gas.