What are the 3 states of matter and how are their particles arranged?
Solid, liquid and gas.
All matter is either in a solid, liquid or gaseous state. As an example: ice is a solid made up of water (H2O) molecules arranged in a crystal pattern. All solids have a crystalline structure. If ice is heated it will melt, losing its structure and becoming a liquid. Heating further will eventually cause the liquid water to boil and assume a gaseous state (steam).
Interesting facts: we think of glass as a solid, but it is in fact an amorphous substance ( it lacks a crystal structure) and is regarded as a super cooled liquid (glass flows, but very, very, slowly.
When matter is heated to extremely high temperatures ( such as on the surface of a star or in a nuclear explosion or in the area of a lightning strike ) it assumes a fourth state which we call plasma.