Group VIIA is the group of the most reactive non-metals.Hence, there is difficulty to gain electrons down the group.Nuclear attraction between the protons and incoming electron decreases.Reactivity decreases down the group due to decrease in electronegativity. Helium is used as a protective gas in growing silicon and germanium crystals, in titanium and zirconium production, and in gas chromatography.Group IA is the group of the most reactive metals.These gases are inert, have very low electron affinity. Hence, it is easy to lose electrons down the group. Noble gases are monoatmic elements occupying the last-right column (group 0) in the periodic table.Nuclear attraction between the protons and valence electrons decreases.Reactivity increases down the group due to increase in electropositivity.s-block elements are (IA, IIA), p-block elements are (IIIA to VIIA, 0) and metalloids are B, Si, As (Arsenic), Ge (Germanium) and Sb (Antimony). There is an annoying drawback in that the element helium is removed from its usual place among the noble gases and moved to join the alkaline earths like.In many of the groups, the member elements have similar. They are, metalloids, alkali metals, alkaline earth metals, transition metals, other elements, non-metals, halogens, noble gases and rare earth elements. Transition or d-block elements are IB, IIB,………VIIB, VIII The elements present in the periodic table are classified under different groups, depending on their chemical and physical properties.Normal or Representative elements are IA, IIA, IIIA, ….VIIA, 0.15 elements from 57La (Lanthanum) to 71Lu (Lutetium) and other 15 elements from 89Ac (Actinium) to 103Lw (Lawrencium) are f-block or Inner transition elements.duplet (He) and octet state (Ne, Ar etc.) so they don’t react with other elements. They have stable electronic configuration i.e.