Question

1. Rank the following element from the least electronegative (1) to most electronegative (6)

Si

Ca

P

Ba

F

N

2. A chemical bond between which of the following elements whold be considered nonpolor covalent? (select all the apply.)

A) H-C

B) C-O

C) Be-Cl

D) C-S

E) F-Cl

F) H-N

G) K-Cl

H) Si-P

I) Mn-O

J) B-N

Answer 1

electronegativity decreases down in a group : Ba < Ca , ,, P <N same group members
electronegativity increases from left to right in a period Si < P ,,,, N < F
Since Ba is below Ca in 2nd group , Ba has least value
Si and P are in same period So Si has less value than P
All can be solved using periodic table

Hence answer : Ranking elements in the increasing order of electro negativity
as
Ba < Ca < Si < P < N < F

Ba :1

Ca :2

Si :3

P;4

N:5

F;6

METAL AND NON METAL BONDS ARE IONIC .Hence they will be purely
ionic.
let us find out electronegativity difference between atoms
in covalent bond . When the difference is small, the compound
will be covalent
A) H-C
DIFFERENCE in electronegativity
dE.N = 2.56 -2.26 = 0.3

B) C-O
dE.N = 3.44-2.55 = 0.89 : polar

C) Be-Cl
dE.N = 3.16 -1.57 = 1.59 ;polar

D) C-S
dE.N = 2.58 -2.56 = 0.02 ; nonpolar

E) F-Cl
dEN = 3.96 - 3.16 = 0.8 : polar

F) H-N
dEN = 3.04 -2.20 =0.84 : polar

  
G) K-Cl = ionic

H) Si-P =
dEN = 2.19-1.90 = 0.29

I) Mn-O= ionic bond

J) B-N =

dEN = 3.04 - 2.04 =1 : polar

dE.N value smaller than 0.5 considered as covalent

hence answer is

A)C-H and

D) C-S
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Thank you