Question

Answer the following.
34.
In the following table, are given eight elements A, B, C, D, E, F, G and H (here letters are not
the usual symbols of the elements) of the Modern Periodic Table with the atomic numbers of
4
the elements in parenthesis.
Period
Group 1 Group 2
2
A (3)
E (4)
3
B (11)
F(12)
C(19)
G (20)
5
D (37)
H (38)
What is the electronic configuration of F?
ii) What is the number of valence electrons in the atom of F?
iii) What is the number of shells in the atom of F?
iv) Write the size of the atoms of E, F, G and H in decreasing order, State whether F is a metal
or a non-metal.Out of the three elements B, E and F, which one has the biggest atomic size?

​

Answer 1

Answer:

(i) Electronic configuration of F(12) is 2, 8, 2.

(ii) There are 2 valence electrons in the atom of F.

(iii) There are 3 shells in the atom of F.

(iv) The atomic size increases as we go from top to bottom of a Group in the periodic table due to the increment in shells. So the size of atoms in the decreasing order is H > G > F > E.

(v) F has 2 valence electrons. To achieve the octet, it will tend to donate 2 electrons. So it is a metal as metals have the tendency to lose electrons.

(vi) The atomic size increases as we go from top to bottom of a Group in the periodic table due to the increment in shells. The atomic size decreases as we go from left to right of a period. So, among the 3 elements given, B has the biggest atomic size