Question

7. Choose the bond that is least polar (how would you do this without looking at an electronegativity chart)

a. P-F

b. C-F

c. C-Cl

d. C-Br

e. C-I

8. Using periodic trends, place the following in order of increasing ionic character.( Please explain)

Si-P, Si-Cl,Si-S

9. How do you calculate the bond order of resonance structures (Please explain.)

Answer 1

7)As you move down the group electronegativity decreases,and along the period electronegativity increases.

By simply studying the positions of the pair of atoms in the periodic table ,we can determine the polarity of the bond between the given atom pairs.

This suggests- 1)a metal is more electropositive than a non-metal.

2) A higher metal in a group is more electropositive ,while a higher non-metal in a group is less electronegative.

3) more the difference of electronegativity .more polar is the bond.

The order of electronegativity would be -

1)As both atoms in the pairs are non-metals-C-F>P-F>C-Cl>C-Br [more the difference of electronegativity .more polar is the bond.]

2) more polar means more ionic character

Si-P<Si-S<Si-Cl (more the difference of electronegativity .more polar is the bond.]

3)

Resonance=when more than one structure exists for a molecule or ion group,

Bond order= number of bound pairs of electrons(or no of bonds) /number of atoms bonded

eg.