The short from electronic configurtion of two elements are [Ar] `4s^1 and [Ne]3p^5`. Identify the two elements.

The electronic configuration of valence shell of Cr in the ground state as 3d^(5)4s^(1) in stead of 3d^(4)4s^(2) . Give reason.

Nitrogen and phosphorus belong to group 15 of the periodic Table. Write the electronic configuration of these two elements.

The electronic configuration of atoms A, B, C are given below A = 1s^2 2s^2 2p^6 3s^1 B = 1s^2 2s^2 2p^6 3s^2 3p^5 C = 1 s^2 2s^2 2p^6 3s^2 3p^6 4s^1 Name the elements

Name two elements that have two electrons in their outermost shells.

A and B are two sets such that (A xx B) consists of 6 elements. If three elements-of (Axx B) are (1, 3), (2, 5) and (3, 3), find the remaining elements of (A xx B) .

Let R be the relation defined in the set A={1,2,3,4,5,6,7,8,9} by R={(a,b,):" both a and b are either odd or even"} . Show that R is an equivalence relation. Further show that all the lements of the subset {1,3,5,7,9} are related to one another and all the lement of the subset {2,4,6,8} are related to one another but no element of the subset {1,3,5,7,9} is related to any element of the subset {2,4,6,8} .