Question

Give the basic demarkation of the Modern Periodic Table into metals, metalloids and non-metals with special reference to halogens and noble gases.

Answer 1

Modern Periodic Table is the arrangement of elements in increasing order of atomic numbers.
There are total 118 elements, the first element i.e. the atomic number 1 is Hydrogen and the last element i.e. the atomic number 118 is Ununoctium.

The elements are categorized mainly into 4 types, and these are:

1. Reactive Metals: They are placed in the extreme left of the periodic table.
2. Weak Metals: They are placed in the middle of the periodic table.
3. Non-metals: They are placed in the upper right corner of the periodic table, and maybe subset further as halogens and noble gases.
4. Metalloids: They have the properties of both the metals and non-metals.

Metals	Metalloids	Non-metals - 17
91	7	General- 7 H, C, N, O, P, S, Se Halogens- 4 F, Cl, Br. I, [At] Nobel gases- 6 He, Ne, Ar, Kr,Xe, Rn

The above demarkation may vary, since the nature of some elements is still under research.