Answer:
Explanation:
The net force on electron is electrostatic force between electron and proton in the nucleus .
Fc = 
This provides the centripetal force for the circular path of electron around the nucleus .
Centripetal force required = 
So



Argon monatomic in nature because it is a noble gas and has completely filled shells and thus does not form a bond with other elements.
B. Three are lost creating Al+3. Because atoms have and equal amount of Protons and Electons when neutral losing 3 electrons will create a positive Al ion Al+3