To answer this question lets start with a bit of revision about the states of matter and its
properties.(distinguishing features or differences). Matter is defined as anything that has a mass and
takes up space. It is all around us and is all the things you can touch and see. The three main states.....
Tightly packed together/Regular pattern, held together by forces called bonds/Cannot move but can vibrate in place/Maintains shape and space
Close together/Random arrangement, form weak bonds (keep together but can move)/Can move around each
other/Changes shape to the shape of the container but takes up the same amount of space
Far apart/Random arrangement, no bonds (do not stay together)/Move quickly in all directions/Changes shape and fills the space, also under pressure can be compressed into smaller spaces
There are other states of matter that are only seen in extreme conditions, for example plasma, which occurs at very high temperatures e.g. In stars. This is where atoms lose their electrons and the mixture of electrons and
atom nuclei form the plasma state.
So in answer to the question of why the molecules are arranged and act differently (have different properties) in different states is basically ENERGY.!!!
Matter can physically change from one state to another but the substance remains the same. These changes happen as the motion of the atoms are changed by the increase or decrease in energy. These changes can be caused by temperature and pressure, for
- temperature: water freezes to ice under cold temperatures (energy decrease) and when heated to boiling point (energy increased) it becomes steam, which is a gas
- pressure: deep inside the earth solids are changed to liquid, in this case magma, due to the pressure caused by the weight of the layers of the earth pushing down (adding energy).