If we take a piece of copper and chop it up into small pieces continously, finally you will end up with atoms (that is the smallest particle and cannot be seen by our naked eyes and you need the best electron microscope to see this). If you chop the copper atom, you no longer will have copper, but, subatomic particles called : protons, neutrons and electrons.
- Protons are (+ charged) and are isnide the central nucleus of te atom).
- Neutrons (no charge) are inside the central nucleus too.
- Electrons (- charge) are not inside the atom's nucleus but are orbitting in outer energy levels or shells called energy levels.
In a neutral atom, the number of neutrons are equal to the # protons ...
Atom is the smallest particle, characterizing a chemical element, namely the smallest particle of a substance, which by ordinary chemical processes cannot be fragmented into other simpler particles.
The atom consists of a cloud of electrons which are surrounding a dense atomic nucleus. The nucleus contains electrical charges,positively charged, called protons, and neutral electrical charges,called neutrons, being surrounded by the negatively charged electronic cloud.
When the number of electrons and protons is equal, then the atom is electrically neutral, if this thing is not happening, then the atom becomes an ion that can have positive or negative charge. Atom is classified by the number of protons and neutrons: the number of protons determines the atomic number (Z) and the number of neutrons determines the isotopes of that element.
Consider a matter(of any type and of any state i.E solid liquid gas).One might think of this matter consist of small particles.Dalton put a theory about the smallest particles that makes a matter and name it as atoms.So atoms were considered to be the smallest particles in the universe.Further investigation told us that there could be particles smaller than atoms lying inside atoms after the discovery of electron by J.J Thomson.And then other smaller particles. CONCLUSION: Now we have the idea that atom is not the smallest particle but atom has its own world inside it.But you can still say that matter is composed of small particles called atoms,though not the smallest.but there are very small having sizes about 10^-10 meter.Each material consist of atoms of different sizes and nature.