All Elements are obtained in the periodic table & water is Not an element it is a compound.
Answer:
The MO method for N2+ gives the bond order equal to 2.5. But first, we look at the diagram of molecular orbitals for N2 (the bond order for the nitrogen molecule is 3). the N2+ molecule). That is, the bond order for N2+ is 2.5.
Answer:
water
Explanation:
because the others are in compounds and can not be considered as products lonely.
The compound formed by chlorine and barium is 
as the number of valence electrons in barium is 2 and in chlorine is 1. In this compound, barium acts as a cation and chlorine acts as an anion. The formation of the compound is as shown in the image.
Since, barium is an element of Group-2 (alkaline earth metal) so the other element that has a chemical formula most and least similar to the chemical formula of the compound formed by chlorine and barium should be from Group-2 (alkaline earth metal) only which has properties somewhat like barium. So, the element is strontium.
Strontium forms a compound with formula 
in which strontium acts as a cation and chlorine acts as an anion. The formation of the compound is as shown in the image.
