Question

The electro negativities (according to Pauling) of the elements in period 3 of the periodic table are as follows.
The elements are arranged in alphabetical order:
  Al     Cl     Mg      Na      P        S       Si
 1.5     3.0     1.2      0.9     2.1      2.5    1.8
(i) Arrange the elements in the order in which they occur in the periodic table  from left to right.
(The group 1 elements first, followed by the group 2 element and so on, up to group 7)

(ii) Choose the word or phrase from the brackets which correctly completes each of the following statements:
(a) The element below sodium in the same group would be expected to have a ______ (lower/higher) electro negativity than sodium and the element above chlorine which would be expected to have a ______ (lower / higher) ionization potential than chlorine.
(b) On moving from left to right in a given period, the number of shells ______ (remains the same / decreases/ increases).
(c) On moving down a group, the number of valence electrons ______ (remains the same / increases/ decreases).

Answer 1

(i) Na   Mg   Al   Si    P    S    Cl.
(ii) (a) lower, higher.
     (b) remains the same.
     (c) remains the same.