Neutron number

The neutron number is the number of neutrons in an atomic nucleus.

It results from the difference between the mass number and atomic number

And the chemical symbol is usually not attached, unlike the mass number.

The number of neutrons can vary on an item. These variations are referred to as isotopes. The simplest example is the element # 1, hydrogen ( usually no neutron), and the isotope deuterium ( a neutron ), and Tritium (two neutrons).

Due to different numbers of neutrons chemical and physical properties of a substance can be also different. This is only for elements with low atomic number of the case, since the change in mass relative to other isotopes will be higher than for heavier elements (see isotope effect ). Such as C -12 ( six neutrons), so usually carbon, which is the main component of organic molecules and 98.9 % is the most abundant of all the natural C-isotope, a stable atom. By adding two neutrons produced C -14, which radioactively decays into a half-life of 5730 years (this will be used in the radiocarbon method for dating of dead organic tissue).

The neutron number of an atom therefore has influence on whether an atom is radioactive or not.

• Nuclear physics