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
Some fear that they won't be able to have fun anymore if they accept God, some are afraid of what others might think of them if they accept God, some think they are too messed up to have a relationship with God, and the list goes on and on. Who knows why someone would refuse.
Hope this helps~!
~{Oh Mrs.Believer}
There are many combinations because it is not all about the number of chemicals, but also about the size of the strand. The longer the strand the more combinations there are and more variations and various lengths provide various results.
Hey there!:
Volume in mL :
1.71 L * 1000 => 1710 mL
Density = 0.921 g/mL
Therefore:
Mass = Density * Volume
Mass = 0.921 * 1710
Mass = 1574.91 g
Answer:
23.2 g of Al will be left over when the reaction is complete
Explanation:
2Al + 3S → Al₂S₃
1 mol of Al = 26.98 g
1 mol of S = 32.06 g
Mole = Mass / Molar mass
63.8 g/ 26.98 g/m = 2.36 mole of Al
72.3 g / 32.06 g/m = 2.25 mole of S
2 mole of Aluminun react with 3 mole of sulfur
2.36 mole of Al react with (2.36 .3)/2 = 3.54 m of S
As I have 2.25 mole of S, and I need 3.54 S, is my limiting reagent so the limiting in excess is the Al.
3 mole of S react with 2 mole of Al
2.25 mole of S react with (2.25 m . 2)/3 = 1.50 mole
I need 1.50 mole of Al and I have 2.36, that's why the Al is in excess.
2.36 mole of Al - 1.50 mole of Al = 0.86 mole
This is the quantity of Al without reaction.
Molar mass . mole = Mass → 26.98 g/m . 0.86 m = 23.2 g
