only this first question which has a number 3 in front

3.What estimates of the cation-anion distance would be obtain for these four compounds using their bonding atomic radii? (Note: these values are also in Figure 7.7 but are different from the ionic radii.) For each of the four compounds, calculate the difference between the predicted ionic bond distance, which you calculated in problem 1, and predicted atomic bond distances you calculated in this problem. Again, assuming that we have an accuracy of 0.04Å in the measurement, which molecule if your predictions are less or more accurate using the atomic radii prediction method. why might one prediction method be more appropriate to use than the other in certain molecules ?

Calculate the difference between the experimentally measured ion-ion distances provided at the beginning of this assignment and the ones you have predicted in problem 1. Assuming that we have an accuracy of 0.04Å in the measurement, which molecule if your predicted ion-ion distances are accurate or not accurate with respect to their experimental ion-ion distances

previous question with answer:

In the ionic compounds LiF, NaCl, KBr, and RbI, the measured cation-anion distances are 2.01 Å (Li-F), 2.82 Å (Na-Cl), 3.30 Å (K-Br), and 3.67 Å (Rb-I), respectively.

1. Predict the cation-anion distance of each ionic compound above using the values of ionic radii given in Figure 7.7 on page 257 in the textbook.

LiF

the ionic radius of cation Li+ = 0.90A

The ionic radius of anion F-=1.19A

=0.90A + 1.19A

=2.09A

NaCI

the ionic radius of cation Na + = 1.16A

The ionic radius of anion CI-=1.67A

=1.16A + 1.67A

=2.83A

KBr

the ionic radius of cation K+ = 1.52A

The ionic radius of anion Br-=1.82A

=1.52A + 1.82A

=3.34A

RbI

the ionic radius of cation Rb+ = 1.66A

The ionic radius of anion I-=2.06A

=1.66A + 2.06A

=3.72A