How to to deduce the valency of elements? To deduce the valency of elements, there is a need to understand the atomic numbers of elements if we can really predict the valency of elements.
Valency is the number of electrons gained or lost in order to form ions. Valence electrons can be deduced from the atomic number of elements how can you do this this can be first the electron configuration on a mean the item configuration and turn about the shell configuration for example if the atomic number of an element is 14, then the configuration can be 2,8,4 so the four electrons in the outermost Shell represent the valence electrons. The valence electrons are the electrons in the outermost shell of an atom but are very careful here; valence electrons are not the same as the valency of an atom.
For metals, the valence electrons are the same as the valency of the atom but for nonmetals, the valence electrons are actually different from the valency of an atom.
Let me explain this;
I’m going to use different elements to illustrate how to get the valency of elements and going to use two metals and two non-metals so for metals you’re going to use sodium and calcium why 40 metals are going to use sulphur and oxygen.
for sodium, the atomic number is 11 and the configuration is 281 so ultimately sodium has one electron in its outermost shell, therefore, means that the valence electrons in sodium are 1 and the valence also is one remember we define valency as a number of electrons lost or gained in order for an atom to form an ion. For sodium to form ion sodium will need to give out only one electron to form a positive ion.
In the same vein, calcium has an atomic number of 20 and the configuration of calcium is 2882 therefore calcium has two valence electrons and the valency of calcium also is 2 +.
The non-metals are quite different because the valence electrons differ from the valency of non-metals I will or straight this just using oxygen and sulphur.
General tule of the valency of first 20 elements
oxygen has an atomic number of eight and its electrons the electron configuration is 26 if they are full means that oxygen has 6 electrons in the outermost shell so the valence electrons are six but the valency of oxygen is 2 – so you can see that 4
For metals, to get the valency you ask yourself how many electrons do I need to complete the shell of an atom you know as in most cases I want to attain the octet configuration or the duplex configuration so if you have 2,6 electrons in the outermost Shell to attend the octet configuration, you will need two electrons more therefore since you need to gain two electrons then the valency of oxygen is 2 -.
first of all for sulphur the atomic number is 16 and the number of electrons is 16 too. Please remember that in a neutral atom the number of electrons equals the number of protons because your question of sulphur is 286 so it means the valence electrons are six and then the valency is 2 –