Answer
The Lewis symbol for $Br$ atom is in the diagram.
Work Step by Step
RULES TO WRITE LEWIS SYMBOL
- Find out the number of valence electrons in the atom.
- Write the element symbol and around it present each valence electron with one dot to the top, bottom, right or left of that symbol.
- Spread out the dots as much as possible (so there would be minimum electron-electron repulsions), and no spots can hold over 2 electrons.
1) $Br$ is in group 7A, so it has 7 electrons in the outermost occupied shell. Therefore, $Br$ has 7 valence electrons.
2) That means in the Lewis symbol, there will be 7 dots.
The first 4 dots would each occupy a single spot.
Then since each spot cannot hold more than 2 electrons, the last 3 electrons cannot all go into one spot. Instead, they would spread out: each would go into a spot that is already occupied by 1 electron.
Eventually, 3 spots would have 2 electrons and 1 spot has only 1 electron.
