How many valence electrons does bromine have?

 How many valence electrons does bromine have?

Answer:

Bromine  has seven valence electrons.

Explanation:

To find out the number of valence electrons in a bromine atom,we need to look at the periodic table.

The position of bromine in the periodic table  is in group VIIA.For main group elements,valence electrons are equal to the group number.So,bromine atom has seven valence electrons in its valence shell or outermost energy level.

Again, bromine is an element of group 17.Now just consider the unit place digit from group number.You are getting 7 which is equal to the number of valence electrons in bromine.

Here is the another way to find out the valence electrons of bromine.

The symbol of bromine is Br and the atomic number of bromine is 35.So,it has thirty five electrons totally.

Now do the electronic configuration of bromine.

Br(35) =1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p5

             =[Ar] 3d10 4s2 4p5

[Tip: Complete filled d orbital is not considered as part of  valence shell or energy level]

The valence shell is the outermost shell and the electrons that are present in valence shell is called valence electrons.

The valence shell or energy level can be identified by the highest value of principal quantum number,n.Here the highest value of n is 4.So,the valence shell is the 4th shell or energy level.

In 4th shell ,we get seven valence electrons.So each bromine has seven valence electrons.

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