question_answer

Write down the electronic configuration of first 5 elements in the periodic table mentioning their energy levels.  

Answer:

 (i) Hydrogen, atomic number = 1 Electronic configuration (ii) Helium, atomic number Electronic configuration =2 (iii) Lithium, atomic number = 3 Electronic configuration (iv) Beryllium, atomic number = 4 Electronic configuration (v) Boron, atomic number = 5 Electronic configuration