(a) The electronic configurations of atoms of elements A, B, C and D are given as follows: A. Is\(^2\)2s\(^2\)2p\(^2\); B. 1s\(^2\)2s\(^2\)2sp\(^1\) ; C. 1s\(^2\)2s\(^2\) 2p\(^1\) ; D. 1s\(^2\) 2s\(^2\)

(I) Arrange the elements in order of increasing atomic size, giving reasons

(ii) State which of the elements I. is divalent II. contains atoms with two unpaired electrons in the grouped state. Ill, readily loses one electron from its atom during chemical bonding IV. belongs to group Ill in the Periodic Table.

 

(b)(i) State one difference between electrovalent and covalent bonds.

(ii) Name two other bonds apart from the ones in (b)(i) above which bind atoms and molecules together.

(iii) State two characteristics of a covalent compound.

 

(c)(i) What is isotopy?

(ii) Illustrate with suitable example

(iii) Two isotopes of Z with mass numbers 18 and 20 are in the ratio 1:2 Determine the relative atomic mass of Z.

 

(d)(i) Which of the following elements: calcium, fluorine, iodine neon, magnesium and helium are I. halogens II. noble gases Ill. alkaline earth metals.

(ii) Write a balanced equation for the bombardment of \(^7_3Li\) with protons to produce \(^8_4\beta\) and \(\gamma\)-rays
(iii) State one use of radioactive isotopes.