CHEMIST

Atom      

                                                                                                               Atom is a basic unit of matter, which consists of atomic nuclei and negatively charged electron cloud surrounding it. The nucleus consists of positively charged protons and electrically neutral neutrons (except hydrogen-1 nucleus, which has no neutrons). Electron-electron in an atom bound to the nucleus by the electromagnetic force. Collection of atoms can likewise bind to each other, and form a molecule. Atom containing the number of protons and electrons the same neutral, while containing a number of different protons and electrons are positive or negative and is called ions. Atoms are grouped based on the number of protons and neutrons contained in the atomic nucleus. The number of protons in an atom determines the chemical element the atom, and the number of neutrons determines the isotope of the element.The term comes from the Greek atom (ἄτομος / Atomos, α-τεμνω), which means it can not be cut or something that can not be subdivided. The concept of atoms as a component that can not be subdivided first proposed by the philosophers of India and Greece. In the 17th century and the 18th, the chemists laid the foundations of this idea by showing that certain substances can not be divided further using chemical methods. During the late 19th century and early 20th century, physicists had found the structure and components of subatomic particles in atoms, proving that the 'atom' is not can not be subdivided. The principles of quantum mechanics used by physicists then successfully model the atom.

IONs

 Ions are atoms or a set of electrically charged atoms. Negatively charged ions, which captures one or more electrons, called anions, because he was attracted towards the anode. Positively charged ions, the loss of one or more electrons, called cations, because they are attracted to the cathode. Ion formation process is called ionization. Atoms or groups of atoms are ionized tikatas marked with + n or-n, where n is the number of electrons lost or gained.

Molecule

 Molecule is defined as a group of atoms (at least two) that each bind with very strong (covalent) in a specific arrangement and electrically neutral and sufficiently stabil.

According this definition, different molecules with polyatomic ions. In organic chemistry and biochemistry, the term is used in a less rigid molecule, so that the organic molecules and biomolecules including uncharged molecules were considered.

In the kinetic theory of gases, the term molecule is often used to refer to any gas particles komposisinya.Menurut without relying on this definition, a noble gas atoms is considered as a molecule, although these gases consist of a single atom is not bonded.

A molecule may consist of atoms berunsur same (eg oxygen O2), or composed of different elements (eg water H2O). Complex atoms and associated non-covalently (eg bound by hydrogen bonds and ionic bonds) is generally not regarded as a single molecule.