Question

What is the formal charge on the bromine atom in hbr?

Answer 1

Formal Charge is defined as the charge an atom in a molecule has, assuming that whatever the electronegativity, the electrons in all chemical bonds are shared equally between atoms.
It can be calculated as: number of valence electrons - number of bonds - number of electrons surrounding Br in the Lewis structure. 
The number of valence electrons of Bromine is 7.
The number of bonds is 1 (it is bonded only to hydrogen). 
The number of electrons surrounding it is 6. (because there is only one bond).
So, the formal charge is:
7 - 1 - 6 = 0.

Answer 2

Answer :  The formal charge on the bromine atom in HBr is, 0

Explanation :  

First we have to draw Lewis-dot structure of HBr.

As we know that hydrogen has 1 valence electrons and bromine has '7' valence electrons.

Therefore, the total number of valence electrons in HBr = 1 + 7 = 8

According to Lewis-dot structure, there are 2 number of bonding electrons and 6 number of non-bonding electrons.

Now we have to calculate the formal charges on bromine atom in HBr.

Formula for formal charge :

$\text{Formal charge}=\text{Valence electrons}-\text{Non-bonding electrons}-\frac{\text{Bonding electrons}}{2}$

$\text{Formal charge on }H=1-0-\frac{2}{2}=0$

$\text{Formal charge on }Br=7-6-\frac{2}{2}=0$

Therefore, the formal charge on the bromine atom in HBr is, 0

The Lewis-dot structure are shown below.