Define the following
1 Valency of an element with 5 eg.
2 Valence electron of an element with 5 eg.
Define the following
1 Valency of an element with 5 eg.
2 Valence electron of an element with 5 eg.
Valency is the combining capacity of an element.
Valency is the number of electrons that a neutral atom of an element loses or gains to have noble gas electronic configuration (to become stable).
Examples...
1)Sodium(atomic no.=11) (2,8,1) can lose an electron to become stable (2,8) electronic configuration of closer noble gas Neon. So the valency of Sodium is 1.
2)Similarly Valency of Calcium, Magnesium is 2 as they loses two electrons. Calcium and magnesium should lose 2 electrons to gain octet.
3)Valency of Aluminium is 3 since it can lose three electrons.
On the other hand,
4)Valency of Chlorine(atomic no.= 17)(2,8,7) is 1 since it needs only 1 electrons to become stable (2,8,8) like nearest noble gas Argon(atomic no.18).
5)Similarly valency of Oxygen is 2 since it needs 2 electrons.
No matter electrons are gained or lost, valency is always positive.
Valence electron of an element
Valence electrons are the electrons in outermost shell of an element.
Examples-
1)Sodium(atomic no.=11) (2,8,1) , It has 1 electron in outermost M shell. 1.So valence electron is
2)Similarly Calcium, Magnesium have 2 electrons in their outerost shells.So valence electron of both are 2 each.
3)Aluminium has 3 electrons in outer shell.So number of valence electrons in Aluminium is 3
On the other hand,4)Chlorine(atomic no.= 17)(2,8,7)
It has 7 electrons in outer shell. So, number of valence electrons is 7.
5)Similarly Oxygen has 6 electrons in outer shell.So, number of valence electrons is 6 in Oxygen.
For metals, number of valence electrons= valency
For non metals like oxygen, chlorine, number of valence electrons=8- valency
Valency is the combining capacity of an element.
Valency is the number of electrons that a neutral atom of an element loses or gains to have noble gas electronic configuration (to become stable).
Examples...
1)Sodium(atomic no.=11) (2,8,1) can lose an electron to become stable (2,8) electronic configuration of closer noble gas Neon. So the valency of Sodium is 1.
2)Similarly Valency of Calcium, Magnesium is 2 as they loses two electrons. Calcium and magnesium should lose 2 electrons to gain octet.
3)Valency of Aluminium is 3 since it can lose three electrons.
On the other hand,
4)Valency of Chlorine(atomic no.= 17)(2,8,7) is 1 since it needs only 1 electrons to become stable (2,8,8) like nearest noble gas Argon(atomic no.18).
5)Similarly valency of Oxygen is 2 since it needs 2 electrons.
No matter electrons are gained or lost, valency is always positive.
Valence electron of an element
Valence electrons are the electrons in outermost shell of an element.
Examples-
1)Sodium(atomic no.=11) (2,8,1) , It has 1 electron in outermost M shell. 1.So valence electron is
2)Similarly Calcium, Magnesium have 2 electrons in their outerost shells.So valence electron of both are 2 each.
3)Aluminium has 3 electrons in outer shell.So number of valence electrons in Aluminium is 3
On the other hand,4)Chlorine(atomic no.= 17)(2,8,7)
It has 7 electrons in outer shell. So, number of valence electrons is 7.
5)Similarly Oxygen has 6 electrons in outer shell.So, number of valence electrons is 6 in Oxygen.
For metals, number of valence electrons= valency
For non metals like oxygen, chlorine, number of valence electrons=8- valency
