What is a mass number?
The atom mass number determines the number of particles in the core. It is the sum of the number of protons and neutrons. In scientific writing, the mass number is usually placed on the upper left part of the atom symbol. When serving together with the atomic number or the number of protons, the mass number of the atom and isotope element will say.
Atom consists of protons, neutrons and electrons. Both protons and neutrons are located in the atom core and weigh about 1,800 times larger than mobile electrons. Protons and electrons have opposite electric charges; To make the atom electrically neutral, the number of protons must equal the number of electrons. Neutrons have no electric charge.
The number of protons in the atomic core determines which element is an atom. For example, an atom with eight protons is an oxygen atom. However, the number of neutrons in the atom may vary somewhat and remain the same element; These varieties are called isotopes. The oxygen atom may contain eight, nine or 10 neutrons and still be stable. Adding the number of protons and neutrons together gives weight nothe number.
Conventions are commonly used to represent atoms information in writing. The atom symbol in the periodic table indicates the atomic number. The mass number is located in the Superscript position to the left of the atom symbol. Clean electric charge, if present, is written in the heading position on the right. This three information reveals the total number of protons, neutrons and electrons.
The existence of various isotopes is the result of a radioactive decay. One of the four basic forces of natural forces, a weak nuclear force, causes atoms to release energy without any contact with other mass. Two protons and two neutrons escape atommzel in alpha. Neutron can turn into proton in beta. In this case, the weight number remains the same, but the atomic number will increase by one.
It is important to distinguish the mass number from the atomic mass. The mass number is always a whole number without associationunits. Atomic mass is a measurement of atom mass and must have weight units. While any weight unit is valid, the most common unit used for atomic mass is an atomic mass. One atomic weight unit is equal to 1.66 x 10
-24 grams.