The chemical bond between which two atoms is most polar?
(1) C–N (3) S–Cl
(2) H–H (4) Si–O
How do you find out?
To determine which chemical bond is most polar, you need to consider the electronegativity difference between the two atoms involved in each bond. Electronegativity is a measure of an atom's ability to attract electrons towards itself in a bond.
The greater the electronegativity difference between two atoms, the more polar the bond becomes. The difference in electronegativity can be found by referring to the periodic table of elements.
In this case, let's find the electronegativity difference for each pair of atoms:
(1) C-N:
The electronegativity of carbon (C) is 2.55, and the electronegativity of nitrogen (N) is 3.04. The electronegativity difference is |2.55 - 3.04| = 0.49.
(2) H-H:
Hydrogen (H) has an electronegativity of 2.20. Since both atoms are the same, there is no electronegativity difference (0.00).
(3) S-Cl:
The electronegativity of sulfur (S) is 2.58, and the electronegativity of chlorine (Cl) is 3.16. The electronegativity difference is |2.58 - 3.16| = 0.58.
(4) Si-O:
The electronegativity of silicon (Si) is 1.90, and the electronegativity of oxygen (O) is 3.44. The electronegativity difference is |1.90 - 3.44| = 1.54.
Comparing the electronegativity differences, we find that:
(1) C-N: 0.49
(2) H-H: 0.00
(3) S-Cl: 0.58
(4) Si-O: 1.54
Among the given options, the bond with the highest electronegativity difference and, hence, the most polar bond is Si-O (option 4).
To determine which chemical bond is most polar, you can look at the electronegativity difference between the two atoms involved in the bond. Electronegativity is a measure of an atom's ability to attract shared electrons in a chemical bond.
The greater the electronegativity difference between two atoms, the more polar the bond. A higher electronegativity difference means that one atom will have a stronger pull on the shared electrons, resulting in an uneven distribution of charge.
So, let's examine the electronegativity values of the atoms involved in each of the given chemical bonds:
(1) C–N:
Carbon (C) has an electronegativity of 2.5, and nitrogen (N) has an electronegativity of 3.0. The electronegativity difference is 3.0 - 2.5 = 0.5.
(2) H–H:
Both hydrogen (H) atoms have the same electronegativity value, which is 2.1. The electronegativity difference is 2.1 - 2.1 = 0.
(3) S–Cl:
Sulfur (S) has an electronegativity of 2.5, and chlorine (Cl) has an electronegativity of 3.0. The electronegativity difference is 3.0 - 2.5 = 0.5.
(4) Si–O:
Silicon (Si) has an electronegativity of 1.8, and oxygen (O) has an electronegativity of 3.5. The electronegativity difference is 3.5 - 1.8 = 1.7.
Comparing the electronegativity differences, we can conclude that the bond between Si and O (option 4) is the most polar, as it has the highest electronegativity difference of 1.7.
Look up the electronegativity of each and subtract. The larger the number the more polar.
C = about 2.5
N = about 2.0
Difference is about 0.5.