Atom is a very small unit in every material that is around us. Atom consists of three types of subatomic particles:
- electrons, which have a negative charge;
- protons, which have a positive charge;
- neutron, which is not charged.
Each element is unique differentiated by the number protons contained in the atom of these elements. Every atom has the number of electrons that are equal to the number of protons; when there is a difference in these atoms called ion.
Many other elements are created by humans, but they are usually unstable and spontaneously transformed into a naturally stable chemical element through a process of radioactivity.
Even though there are only 91 elements in nature, they can occur bonds with each other into molecules and other types of chemical compounds. Molecules are formed of many atoms. The water molecule is a combination of 2 hydrogen atoms and 1 atom oxygen.
Atomic nucleus
The center of the atom is called the atomic nucleus or nucleus. The atomic nucleus consists of protons and neutrons. The number of protons in the atomic nucleus is called the atomic number, and determines its form elements what atoms are.
The size of the atomic nucleus is much smaller than the size of the atom itself, and almost partly
mostly made up of protons and neutrons, almost absolutely no contribution from electron.
Protons and neutrons have almost the same mass, and the sum of the two masses is called the mass number, and it weighs almost the same as. The mass of the electrons is very small and doesn't contribute much to the atomic mass.
The number of protons and neutrons determines the type of the nucleus or atomic nucleus. Protons and
neutrons have almost the same mass, and the number combination, the number of masses, on average
equal to the atomic mass of an atom. The combined mass of electrons is very small ratio to the mass of the nucleus, because the weight of the protons and neutrons is almost 2000 times the mass of an electron.
Neutron
Neutrons or neutrons are subatomic particles which are not charged (neutral) and has a mass of 1.6749 × 10-27 kg, slightly heavier than a proton. The atomic nucleus of most atoms are made up of protons and neutrons.
The main difference between neutrons and other subatomic particles is that they are not charged. This nature of the neutrons made his discoveries more backward, and very penetrating, made it difficult to observe in person and made it very important as an agent in nuclear change.
Proton
In physics, a proton is a subatomic particle with a positive charge of 1.6 × 10-19 coulombs and a mass of 1.6726231 × 10-27 kg, or about 1800 times the mass of a electron.
An atom usually consists of a number of protons and neutrons in the nucleus (middle) atom, and the number of electrons surrounding that nucleus. In charged atoms neutral, the number of protons will equal the number of electrons. The number of protons in the section the nucleus will usually determine the chemical properties of an atom. The atomic nucleus is often known as the term nuclei, nucleus, or nucleon (English: nucleon), and the reaction that occurs or related to the nucleus of this atom is called a nuclear reaction.
