Q7 of 24 Page 91

Nitrogen (atomic number 7) and phosphorus (atomic number 15) belong to group 15 of the periodic table. Write the electronic configurations of these two elements. Which of these will be more electronegative ? Why?

Electronic configuration of Nitrogen is 2, 5.

Electronic configuration of Phosphorus is 2, 8, 5.


Nitrogen will be more electronegative than Phosphorus because its atom has small size due to which the attraction of its nucleus for the incoming electron is more.


More from this chapter

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5

An atom has electronic configuration 2, 8, 7.

(a) What is the atomic number of this element ?


(b) To which of the following elements would it be chemically similar ? (Atomic numbers are given in parentheses)


N (7) F (9) P (15) Ar (18)

 6

The positions of three elements A, B and C in the periodic table are shown below:























Group 16



Group 17



—



—



—



A



—



—



B



C



(a) State whether A is a metal or non-metal.


(b) State whether C is more reactive or less reactive than A.


(c) Will C be larger or smaller in size than B?


(d) Which type of ion, cation or anion, will be formed by element A ?

 8

How does the electronic configuration of an element relate to its position in the modem periodic table ?

 9

In the modem periodic table, calcium (atomic number 20) is surrounded by elements with atomic numbers 12, 19, 21 and 38. Which of these have physical and chemical properties resembling calcium ?