{"id":67,"date":"2016-08-23T16:13:13","date_gmt":"2016-08-23T16:13:13","guid":{"rendered":"http:\/\/www.experimentoscientificos.es\/?p=67"},"modified":"2018-11-16T15:36:59","modified_gmt":"2018-11-16T15:36:59","slug":"numero-oxidacion","status":"publish","type":"page","link":"https:\/\/www.experimentoscientificos.es\/en\/numero-oxidacion\/","title":{"rendered":"Oxidation Number. Valence Electron Layer and Electrons"},"content":{"rendered":"

The atom<\/a> is composed of a nucleus of protons (positively charged) and neutrons and electrons (negatively charged) that circle in orbits around the nucleus. The electrons are responsible for the chemical bonds<\/a> that occur between atoms. Their distribution and number of electrons in the last shell are fundamental in order to establish the different bonds that can be established.<\/p>\n

ELECTRON DISTRIBUTION IN ATOMS<\/h2>\n

The electrons do not circulate freely around the nucleus, but in certain energy levels, in different shells. Depending on the number of electrons in each element (equal to the number of protons, as can be seen from the periodic table<\/a>The energy levels of each element (through the atomic number, the number of protons of each element) will be completed.<\/p>\n

The more complete the last energy level, the more stable an element will be. Likewise, the number of electrons missing or left over to complete the last shell is what will give us the oxidation number<\/strong> of each element and the tendency it will have to be combined with other elements through the chemical bonds<\/a>.<\/p>\n

ELECTRON SHELLS OR ENERGY LEVELS<\/h2>\n

Different levels can hold different numbers of electrons. This is:<\/p>\n\n\n\n\n\n\n\n\n\n\n
<\/th>\ns<\/th>\np<\/th>\nd<\/th>\nf<\/th>\n<\/tr>\n
n = 1<\/b><\/center><\/td>\n
2<\/center><\/td>\n
<\/td>\n<\/td>\n<\/td>\n<\/tr>\n
n = 2<\/b><\/center><\/td>\n
2<\/center><\/td>\n
6<\/center><\/td>\n
<\/td>\n<\/td>\n<\/tr>\n
n = 3<\/b><\/center><\/td>\n
2<\/center><\/td>\n
6<\/center><\/td>\n
10<\/center><\/td>\n
<\/td>\n<\/tr>\n
n = 4<\/b><\/center><\/td>\n
2<\/center><\/td>\n
6<\/center><\/td>\n
10<\/center><\/td>\n
14<\/center><\/td>\n<\/tr>\n
n = 5<\/b><\/center><\/td>\n
2<\/center><\/td>\n
6<\/center><\/td>\n
10<\/center><\/td>\n
14<\/center><\/td>\n<\/tr>\n
n = 6<\/b><\/center><\/td>\n
2<\/center><\/td>\n
6<\/center><\/td>\n
10<\/center><\/td>\n
<\/td>\n<\/tr>\n
n = 7<\/b><\/center><\/td>\n
2<\/center><\/td>\n
6<\/center><\/td>\n
<\/td>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

The way to complete these energy levels can be found by the following Aufbau rule:<\/p>\n

\"Diagrama<\/p>\n

That is, it will first be completed at level 1 with 2 electrons: 1s2<\/sup><\/b>then level 2:\u00a02s2<\/sup>, <\/b>then\u00a02p6<\/sup> \u00a03s2<\/sup>then 3p6<\/sup>\u00a04s2<\/sup>, <\/b>next level 3d10<\/sup>\u00a04p6<\/sup>\u00a05s2\u00a0<\/sup><\/b><\/p>\n

So on and so forth until the full electron configuration is reached:<\/p>\n

1s2<\/sup>\u00a02s2<\/sup>\u00a02p6<\/sup>\u00a03s2<\/sup>\u00a03p6<\/sup>\u00a04s2<\/sup>\u00a03d10<\/sup>\u00a04p6<\/sup>\u00a05s2<\/sup>\u00a04d10<\/sup>\u00a05p6<\/sup>\u00a06s2<\/sup>\u00a04f14<\/sup>\u00a05d10<\/sup>\u00a06p6<\/sup>\u00a07s2<\/sup>\u00a05f14<\/sup>\u00a06d10<\/sup>\u00a07p6<\/sup><\/b><\/p>\n

To determine the electron configuration of an element, simply calculate how many electrons need to be accommodated and then distribute them in the sublevels starting with the lowest energy sublevels and filling in until all the electrons are distributed. An element with a higher atomic number has one more electron than the element before it. The energy sublevel increases in this way:<\/p>\n

VALENCE ELECTRON<\/h2>\n

The\u00a0valence electrons<\/b>\u00a0are the electrons found in the highest energy level or last shell of the atom. They are responsible for bonds between atoms of different elements or between atoms of the same element. The valence electrons are those that will be used in the formation of compounds.<\/p>\n

VALENCE OR OXIDATION NUMBER<\/h2>\n

The number of electrons missing or left over to complete the last shell is called the valence or oxidation number. Here are some rules:<\/p>\n