please answer a p-n type question because i have exam next week !

[rabso]

why arsenic and gallium become a full compound and silicon and boron have a hole ?

 

[raiya_23]

Kindly tell me about the number of electrons in the valence shell of aresnic,gallium,silicon and boron, then I will answer your question

 

[rabso]

Kindly tell me about the number of electrons in the valence shell of aresnic,gallium,silicon and boron, then I will answer your question

arsenic = 5, gallium = 3, silicon = 4, boron = 3.

 

[raiya_23]

To become a compound, each element needs to have eight electrons in its valence shell. Now if arsenic reacts with an element whose valence shell contains three electrons then 5+3=8, it will become a compound same is the case with any other element e.g.

gallium=3, other element=5 (it will become a compound)
silicon=4, other element=4 (it will become a compound)
boron=3, other element=5 (it will become a compound)

However if arsenic combines with an element that has 4 electrons in its valence shell, we will be left with an extra electron (5+4=9) and if it reacts with an element that has 2 electrons in its valence shell in that case we will have deficiency of one electron called a hole (5+2=7), get it?

Other elements will behave the same way

So when aresenic and gallium combine (5+3=8) it becomes a full compound but when silicon and boron combine (4+3=7) there is still vacancy for one more electron called a hole

 

[rabso]

To become a compound, each element needs to have eight electrons in its valence shell. Now if arsenic reacts with an element whose valence shell contains three electrons then 5+3=8, it will become a compound same is the case with any other element e.g.

gallium=3, other element=5 (it will become a compound)
silicon=4, other element=4 (it will become a compound)
boron=3, other element=5 (it will become a compound)

However if arsenic combines with an element that has 4 electrons in its valence shell, we will be left with an extra electron (5+4=9) and if it reacts with an element that has 2 electrons in its valence shell in that case we will have deficiency of one electron called a hole (5+2=7), get it?

Other elements will behave the same way

So when aresenic and gallium combine (5+3=8) it becomes a full compound but when silicon and boron combine (4+3=7) there is still vacancy for one more electron called a hole

i totally get it and i don`t know how to thank you *** bless you

 

[raiya_23]

You are welcome ...and if you wanna thank someone on the forums you can give them points...its that little button at the bottom of the posts ...cheers!