- Matter is anything that occupies the space and has a mass. Matter is made up of tiny and discrete particles that are in constant motion. There are spaces between these particles. The tiny particles may be atoms, molecules and ions.
- An atom is the smallest particles of an element that can take part in a chemical reaction.
- A molecule is a group of two or more atoms which are chemically bonded together.
- An ion is a positively-charged or negatively-charged particle.
- Matter consists of small particles that always move and collide among each other.
- The kinetic theory of matter stated the particles move freely when energy is absorb and move slowly when is release, then they are cooled. This theory used to explain the change physical state of matter. The energy used used by the particles to move, we called it kinetic energy.
- Diffusion is the movement of a fluid from an area of higher concentration to an area of lower concentration. Diffusion is a result of the kinetic properties of particles of matter. The particles will mix until they are evenly distributed. Diffusion occurs slowest in solids, faster in liquids and the fastest in gases.
- Melting is the process by which a substance changes from the solid phase to the liquid phase. Melting point is the temperature at which a solid and liquid phase may coexist in equilibrium. The term applies to pure liquids and solutions.
- Freezing is the process through which a substance changes from a liquid to a solid. All liquids except helium undergo freezing when the temperature becomes sufficiently cold. The freezing point is the temperature at which a liquid changes to a solid.
- Condensation is change in the state of matter from the gas phase to the liquid phase.
- Boiling is the process of transition from the liquid state to the gas state, usually occurring when a liquid is heated to its boiling point. The boiling point is the temperature at which the vapor pressure of a liquid equals the external pressure surrounding the liquid.
- Sublimation is the transition from the solid phase to the gas phase without passing through an intermediate liquid phase.
- Isotopes are atoms with the same number of protons, but differing numbers of neutrons. In other words, the have different atomic weights.
- For any atom:
Number of Electrons = Number of Protons
Number of Neutrons = Mass Number -
Atomic Number
Number of Protons = Atomic Number of the Element