Activity 1.6

1	Classify elements from atomic number 11 to 18 as metals and non-metals depending on the electrons present in the outermost shell.

Ans:	Element Atomic Number Number of electrons in the outermost shell Metal/Non-metal Sodium 11 1 Metal Magnesium 12 2 Metal Aluminium 13 3 Metal Silicon 14 4 (Metalloid) Phosphorus 15 5 Non-metal Sulphur 16 6 Non-metal Chlorine 17 7 Non-metal Argon 18 8 -----

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2	Write the electronic configuration of Mg, K, Ar and F.

Ans:	Element Electronic Configuration Magnesium (Mg) 2, 8, 2 Potassium (K) 2, 8, 8, 1 Argon (Ar) 2, 8, 8 Fluorine (F) 2, 7