Homework 2

Fabianna Gaskin Module 2: Homework 2 EGN3365 Professor Wang January 22, 2023 2.2 Chromium has four naturally occurring isotopes: 4.34% of^50Cr, with an atomic weight of 49.9460 amu; 83.79% of^52Cr, with an atomic weight of 51.9405 amu; 9.50% of^53Cr, with an atomic weight of 52.9407 amu; and 2.37% of^54Cr, with an atomic weight of 53.9389 amu. On the basis of these data, confirm that the average atomic weight of Cr is 51.9963 amu . 4.34% of 50 Cr, with an atomic weight of 49.946o amu 83.79% of 52 Cr, with an atomic weight of 51.9405 amu 9.50% of 53 Cr, with an atomic weight of 52.9407 amu 2.37% of 54 Cr, with an atomic weight of 53.9389 amu Average atomic weight of Cr: 51.9963 amu Average atomic mass= ( 4.34 x 49.9460 ) + ( 83.79 x 51.9405 ) + ( 9.50 x 52.9407 ) +( 2.37 x 53.9389 ) 100 = 5199.632 100 = 51.9963 2.9 Give the electron configuration for the following ions Fe 2+ : 1s 2 2s 2 2p 6 3s 2 3p 6 3d 6 Al 3+ : 1s 2 2s 2 2p 6 Cu + : 1s 2 2s 2 2p 6 3s 2 3p 6 3d 10 Ba 2+ : 1s 2 2s 2 2p 6 3s 2 3p 6 3d 10 4s 2 4p 6 4d 10 5s 2 5p 6 6s 2 Br - : 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 6 O 2- : 1s 2 2s 2 2p 6 2.25 Compute the %IC of the interatomic bond each of the following For TiO 2 . Xti= 1.5 and Xo= 3.5 %IC= [1-e (-0.25)(3.5 – 1.5)^2 ] x 100 = 63.2% For ZnTe. Xzn= 1.6 and Xte= 2.1 %IC= [1-e (-0.25)(2.1 – 1.5)^2 ] x 100 = 6.1% For CsCl. Xcs= 0.7 and Xcl= 3.0