It is not the number of valence electrons that an insulator has that is important. It is the way the valence electrons are "arranged" in the structure of the material that matters. If not all the valence electrons of a substance are "involved" in the structure of the material, then these electrons are said to be free electrons. They move about in the substance, and are free to contribute to electron flow. The metals are examples. In contrast with this, if all the electrons are bound up in a material, they are not free to support current flow, and the material is said to be an insulator. Said another way, if the valence electrons in a material are in a Fermi energy level that overlaps the conduction band for that material, the material is a conductor. In an insulator, the valence electrons are all in Fermi energy levels that are below the conduction band for that material, and it is an insulator. Applying a voltage to an insulator will not "lift" the valence electrons up into the conduction band to allow them to support current flow.
Iodine has 7 valance electrons
Argon has 8 valence electrons.
Iodine has 7 valence electrons.
The valency of nitrogen is 3
Boron has three valance electrons. Boron also has three electtrons in outermost energy shell. The 'Valance' number of electrons tells you how many bonds will form between boron and other atoms. Compare with oxygen . Oxygen has two valance electrons . However, oxygen has 6 electrons in its outermost energy shell. This means that oxygen will form two bonds between other atoms. Thus leaving four electrons uncombined; they are known as 'lone pairs'.
2 valance electrons
There are 27 valance electrons.
Iodine has 7 valance electrons
They have different numbers of valance electrons
6 valence electrons
6 valence electrons
there are six
Two.
none
2
3
1