The electronic configuration of the element which has the largest atomic size is:

1. 2, 8, 5
2. 2, 8, 1
3. 2, 8, 7
4. 2, 1

Rewrite the incorrect statements only by rectifying the incorrect word/s in the statement.

(a) Periodic table is based on the fundamental property atomic weight.

(b) Elements in the periodic table are arranged in seven horizontal rows called 'groups', which ends with an element having one electron in outermost shell.

(c) Period numbers i.e., 1, 2, 3 signifies the no. of electron shells of an element e.g. period 3 element 'Mg' has 2 shells.

(d) Across a period from left to right the no. of electron shells increases by one & the valence electron remains same.

(e) Group numbers i.e., 1, 2, 3 signifies the number of electron shells of an element.

(f) Down a sub-group, the valence electrons & the number of electron shells remains same.

Give reason — Noble gases are considered, unreactive elements.

Give reason — In a sub-group the chemical properties of elements remain similar.