Question 2
Write Lewis dot symbols for atoms of the following elements: Mg, Na, B, O, N, Br.
G.N Lewis introduced symbols to represent the valence electrons in the atoms.They are called Lewis symbols, where valence electrons are shown as dots surrounding the symbol of atom or ion.
Mg: Mg belongs to 3rd period & 2nd group of periodic table & has 2 electrons in the valence shell, therefore lewis structure is 
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Na: Na has electronic configuration of [Ne]10 3s1, i.e it has 1 electron in outer most shell, Hence, the Lewis dot structure is: 
B: Boron belongs to 2nd period & 13th group with 3 electron in valence shell. Hence, the Lewis dot structure is: 
O: Oxygen has electronic configuration of [He]2 2s2 2p4,i.e having 6 electrons in valence shell. Hence, the Lewis dot structure is: 
Br: There are seven valence electrons in bromine. Hence, the Lewis dot structure is: 
