Question

The electronegativities (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) electronegativity 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/increases/decreases).
(c) On moving down a group, the number of valence electrons __________ (remains the same/increases/decreases).

Answer 1

(i)

Group	1	2	3	4	5	6	7
Element	Na	Mg	Al	Si	P	S	Cl

(ii)
(a) The element below sodium in the same group would be expected to have a lower electronegativity than sodium and the element above chlorine which would be expected to have a higher ionisation potential than chlorine.
(b) On moving from left to right in a given period, the number of shells remains the same.
(c) On moving down a group, the number of valence electrons remains the same.