CHAPTER 2 ATOMIC STRUCTURE AND INTERATOMIC BONDING

EMA3010: Solutions of homework # 1

2.3 (a) In order to determine the number of grams in one amu of material, appropriate manipulation of the amu/atom, g/mol and atom/mol relationships is all that is necessary, as:

# g/amu = = g/amu

(b) 1 gram = 1/ 454 pound

So, there are atoms in a pound-mole of a substance

2.13 (1) EN = = = 0 (2) = 0 = = = = (3) = so, = 2.14

(a) ro = 0.28 nm
Eo= - 4.6eV
ro = 0.279 nm
Eo= - 4.57 eV

2.19 % of ionic character = { 1 - exp[-(0.25) ]} * 100%
For TiO2 , XTi = 1.5 XO = 3.5 % of ionic character = 63.2 % ZnTe , XZn = 1.6 XTe = 2.1 % of ionic character = 6.06 % CsCl , XCs = 0.7 XCl = 3.0 % of ionic character = 73.4 % InSb , XIn = 1.7 XSb = 1.9 % of ionic character = 0.995 % MgCl2, XMg =1.2 XCl = 3.0 % of ionic character = 55.5 %

2.24 When hydrogen is covalently bonded to oxygen (as in H2O), it forms a strong bond in a relatively rigid dipolar configuration. These bonds will form a rigid 3-D structure when water freezes and the volume of H2O expands because of the nature of the configuration. These bonds will break gradually when the temperature is raised higher than the melting point and the 3-D structure is nearly destroyed when it reaches 4oC. That's why the density of water is greater than that of ice and reaches its maximum at 4oC.

Return To: