Based on their position on the periodic table, how many core and valence electrons do the following elements have?
(i) Arsenic
(ii) Antimony
(iii) Strontium
(iv) Beryllium

• A. (i) 5 core electrons & 28 valence electrons(ii) 5 core electrons & 46 valence electrons(iii) 2 core electrons & 36 valence electrons(iv) 2 core electrons & 2 valence electrons
• B. (i) 33 core electrons & 28 valence electrons(ii) 51 core electrons & 46 valence electrons(iii) 38 core electrons & 36 valence electrons(iv) 4 core electrons & 2 valence electrons
• C. (i) 28 core electrons & 5 valence electrons(ii) 46 core electrons & 5 valence electrons(iii) 36 core electrons & 2 valence electrons(iv) 2 core electrons & 2 valence electrons
• D. (i) 28 core electrons & 33 valence electrons(ii) 46 core electrons & 51 valence electrons(iii) 36 core electrons & 38 valence electrons(iv) 2 core electrons & 4 valence electrons

Answer: (C)