Valence electrons are the electrons found in outermost shell surrounding an atomic nucleus. Valence electrons are important because they provide a deep insight into the chemical properties of an element: either electronegative or electropositive in nature, or indicate the bond order of a chemical compound–the number of bonds that can be formed between two atoms. Due to the exchange of electrons present in the final shell, covalent bonds are formed, the number indicates how many bonds are allowed to form.
The most palpable method would be to refer to the atomic configuration of an element and simply count in the outermost shell the electrons. This would be an extremely tedious chore, however, as we may have to rummage through textbooks to search for configurations that we are not familiar with.
There’s no need to worry, though, because there’s a much simpler way to find that coveted number. This is a more generalized approach that requires only one small, shiny, rectangular sheet of paper— the periodic table — to be summoned. To find an element’s number of valence electrons, we only need to refer to the periodic table and look for the position of the element in it.
Valence electrons Periodic Table
The periodic table is a simple collection of all the elements that we have so far found. In ascending order of their atomic numbers, or the number of protons and electrons they contain, the elements are grouped from left to right.
The elements are divided into four categories: main group elements, transition elements, lanthanides and actinides. The latter two are also referred to as elements of internal transition elements. The table contains a total of 18 columns, formally referred to as groups as well as rows, formally referred to as periods. In the sub table above there are 7 rows and 2 rows that distinguish the rarer elements below.
Although the number of shells increasing, the number of valence electrons stays the same as they move down a group. Although valence electrons increase by one over a period of time, the number of shells remains the same. The period number in which an item can be found (row number, to remind you) shows the number of shells surrounding its nucleus.
Characteristics of Valence Electron
Electrons are involved in the chemical bonding of the atom and its reactions. It is said in an atom that it occupies orbitals. The number of an atom’s valence electrons can be derived from the periodic table as it is equal to the atom’s group number. Atoms are most stable when they have a filled valence shell of electrons. Atoms transfer or share electrons so that a filled shell of electrons can be achieved.
Some of valence electron’s key features are;
- The valence electron only occurs in the outermost electron shell for the main group components.
- There may be a valence electron in a transition metal’s inner shell.
- Typically, an atom consisting of a closed shell of valence electrons is chemically inert.
- A valence electron in the form of a photon can either absorb or release energy.
- The electrons of Valence also determine an element’s electrical conductivity. Depending on the nature of the elements, a metal, nonmetal, or metalloid can be used.
Oxygen valance electron
Oxygen is in Group VI, so the oxygen ATOM contains six valence electrons.
Z = 8. For oxygen If the oxygen nucleus has eight protons, the atom must also have eight negative charges, i.e. eight electrons.
Two of these electrons are the inner core and are not intended to be involved in bonding. The remaining 6 are valence electrons that are involved in bonding and structure influences. Normally, two of these electrons combine to form covalent bonds with the electrons of donor atoms (cf. hydrogen). The remaining 4 valence electrons live in lone pairs that are stereo chemically active and affect structure.
Carbon Valence electrons
There are 4 valence electrons in carbon atoms.
Next to the “A” number is the number of valence electrons in the atom of an element in that group.
Carbon has 4 valence electrons in Group 4A.
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