Atom and ion are elementary particles of chemical elements. These particles are carriers of the properties of the elements. They differ in charges: the atom is neutral, and the ion is positively or negatively charged.
Atom - an electrically neutral microscopic particle of a chemical element that determines its properties. The center of an atom is a positively charged nucleus surrounded by an electron cloud, along which electrons move in orbitals. Atoms, adding or donating electrons, turn into ions.
Ions are microscopic electrically charged, monoatomic or polyatomic and chemically active particles. They have a positive (cations) or negative (anions) charge. Ions are formed from atoms or groups of atoms that acquire electrons or, conversely, lose them.
Ions are independent particles found in any state of aggregation. They are found in gases (in the atmosphere), in crystals, in liquids (both solutions and melts) and in plasma (interstellar space.)
Ions in chemical reactions are able to interact with each other, with molecules and atoms. In solutions, these active particles are formed during electrolytic dissociation and determine the properties of electrolytes.
An atom is always electrically neutral, an ion, on the contrary, is a charged particle. For atoms, the outer energy levels are, as a rule, incomplete (the exception is the group of noble gases). For ions, the outer levels are completed.
The ion, in contrast to the atom, is not capable of possessing the properties of a simple substance. For example, metallic potassium enters into a violent reaction with water, the products of which are hydrogen and alkali. And the potassium ions present in the composition of potassium salts do not have similar properties. Chlorine is a yellow-green poisonous gas, and its ions are non-toxic and colorless.
The color of copper is red, and its ions in solutions acquire a blue color. Iodine crystals are gray, vapors are violet, an alcohol solution is red-brown, mixed with starch, it gives a blue coloration. Iodine ions cannot change the color of starch, they are colorless.
- Atoms and ions of one chemical element have a different number of electrons.
- The charge of atoms is zero, for ions it can be positive or negative.
- Ions and atoms have different redox properties.