Electronegativity is the strength an atom has to attract a bonding pair of electrons to itself. When a chlorine atom covalently bonds to another chlorine atom, the shared electron pair is shared equally. The electron density that comprises the covalent bond is located halfway between the two atoms.
But what happens when the two atoms involved in a bond aren’t the same? The two positively charged nuclei have different attractive forces; they “pull” on the electron pair to different degrees. The end result is that the electron pair is shifted toward one atom.
ATTRACTING ELECTRONS: ELECTRONEGATIVITIES
The larger the value of the electronegativity, the greater the atom’s strength to attract a bonding pair of electrons. The following figure shows the electronegativity values of the various elements below each element symbol on the periodic table. With a few exceptions, the electronegativities increase, from left to right, in a period, and decrease, from top to bottom, in a family.
Electronegativities give information about what will happen to the bonding pair of electrons when two atoms bond. A bond in which the electron pair is equally shared is called a nonpolar covalent bond. You have a nonpolar covalent bond anytime the two atoms involved in the bond are the same or anytime the difference in the electronegativities of the atoms involved in the bond is very small.

Now consider hydrogen chloride (HCl). Hydrogen has an electronegativity of 2.1, and chlorine has an electronegativity of 3.0. The electron pair that is bonding HCl together shifts toward the chlorine atom because it has a larger electronegativity value.
A bond in which the electron pair is shifted toward one atom is called a polar covalent bond. The atom that more strongly attracts the bonding electron pair is slightly more negative, while the other atom is slightly more positive. The larger the difference in the electronegativities, the more negative and positive the atoms become.
Now look at a case in which the two atoms have extremely different electronegativities — sodium chloride (NaCl). Sodium chloride is ionically bonded. An electron has transferred from sodium to chlorine. Sodium has an electronegativity of 1.0, and chlorine has an electronegativity of 3.0.
That’s an electronegativity difference of 2.0 (3.0 – 1.0), making the bond between the two atoms very, very polar. In fact, the electronegativity difference provides another way of predicting the kind of bond that will form between two elements, as indicated in the following table.
Electronegativity DifferenceType of Bond Formed0.0 to 0.2nonpolar covalent0.3 to 1.4polar covalent> 1.5ionic
The presence of a polar covalent bond in a molecule can
Divide
Answer:
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Answer:
Since HCl is a strong acid, it completely ionizes, and the pH of HCl in solution can be found from the concentration (molarity) of the H+ ions, by definition equal to 0.100 M. (The conjugate base of the acid, which is the chloride ion Cl–, would also have a concentration of 0.100 M.) The pH is thus –log(0.100) = 1.000.
Explanation:
Notice q=3/2, is half of the original q = 3(<span>1/2</span>)<span>t/28.8
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Answer: The half-reactions represents reduction are as follows.
Explanation:
A half-reaction where addition of electrons take place or a reaction where decrease in oxidation state of an element takes place is called reduction-half reaction.
For example, the oxidation state of Cr in 
is +6 which is getting converted into +3, that is, decrease in oxidation state is taking place as follows.
Similarly, oxidation state of Mn in 
is +7 which is getting converted into +2, that is, decrease in oxidation state is taking place as follows.
Thus, we can conclude that half-reactions represents reduction are as follows.
