Using the part of the periodic table given below, answer the questions that follow. (i) Na has physical properties similar to which elements and why ? (ii) Write the electronic configuration of N and P. (iii) State one property common to fluorine and chlorine.

Using the part of the periodic table given below, answer the questions

1.	Using the part of the periodic table given below, answer the questions that follow. (i) Na has physical properties similar to which elements and why ? (ii) Write the electronic configuration of N and P. (iii) State one property common to fluorine and chlorine.
Answer» Solution :(i) Na has physical properties similar to Li and K. All the three elements have one electron each in the VALENCE shell of their atoms. These are known as alkali metals. However, the element hydrogen has different physical properties since it is not a part of the group of alkali metals. (ii) Electronic CONFIGURATION of N (Z = 7) = 2, 5 Electronic configuration of P (Z = 15) = 2, 8, 5 (iii) Both the elements have seven electrons in the valence SHELLS as their atoms and have VALENCY equal to one. Fluorine (Z = 9) 2, 7 , Chlorine (Z = 17) 2, 8, 7.