Respuesta :

Answer: Helium: atomic number 2. EC 2

Neon: atomic number 10. EC 2,8

hydrogen: atomic number 1. EC 1

magnesium: atomic number 12. EC 2,8,2

chlorine: atomic number 17. EC 2,8,7

Aluminum: atomic number 13. EC 2,8,3

Explanation: hope this helped