Valence electrons:
These are electrons located at the last shell of an atom of an element. For metals, the maxumum is often three electrons (except lead and tin which have four electrons) and for non-metals the valence electrons are from four to maximum of eight valence electrons.
For a metal, the number of valence electrons corresponds to the valency of the element, while for non-metals(8-valence electrons) corresponds to its valency.
Examples: (1) Sodium (metal);valence electron = 1,valency =1 (2) Chlorine(non-metal); valence electrons=7,valency =7 [8-7valence electrons]
Valence shell:
It is the last shell that accommodatesthe valence electrons of an atom of an atom of an element.
These are electrons located at the last shell of an atom of an element. For metals, the maxumum is often three electrons (except lead and tin which have four electrons) and for non-metals the valence electrons are from four to maximum of eight valence electrons.
For a metal, the number of valence electrons corresponds to the valency of the element, while for non-metals(8-valence electrons) corresponds to its valency.
Examples: (1) Sodium (metal);valence electron = 1,valency =1 (2) Chlorine(non-metal); valence electrons=7,valency =7 [8-7valence electrons]
Valence shell:
It is the last shell that accommodatesthe valence electrons of an atom of an atom of an element.