Lesson 6- Electronegativity & Polarity

Question 1

Electronegativity

Answer 1

electronegativity is the ability of an individual atom, when bonded, to attract bonding electrons to itself

Question 2

Ionic bonds are between a metal and a non-metal, and molecular (covalent) bonds are between non-metals, right?

Answer 2

Yes, but there’s a more formal distinction!

However to truly know if it is ionic or covalent we must calculate the difference in the elements’ electronegativities!

Question 3

ΔEN indicates….

Answer 3

Indicates the degree to which a chemical bond is ionic or covalent!

Question 4

0 to 0.4 is…

Answer 4

non polar covalent (They are sharing e- equally)

Question 5

0.41 to 1.69 is…..

Answer 5

polar covalent (unequal sharing)

Question 6

> 1.7 is…

Answer 6

Ionic (no shakring of elections in a bond)

Question 7

What do arrows in our drawings represent?

Answer 7

They point towards the more electronegative atom in the bond

Question 8

Partial charges (δ+ and δ-) are also used to show….

Answer 8

relative charges in a polar covalent bond

Question 9

Polar Molecules

Answer 9

slightly positively charged at one end and slightly negatively charged at the other because of electronegativity differences

ex. Water

-

Question 10

Non-Polar Molecules

Answer 10

All molecular elements are non-polar
No dipole moments and partial charges are drawn!

Question 11

If a molecule has polar BONDS, is the molecule ALWAYS polar?

Answer 11

Not all molecules containing polar covalent bonds are polar molecules!

Question 12

Shapes and polarity of important molecule: Water–>Bent shape

Answer 12

2 bonding pairs (central atom)
2 lone pairs (central atom)
Polar molecule (if polar covalent bonds)

Question 13

Bonding pairs

Answer 13

the # of bonds to the atom (count double/triple bonds as ONE bond)

Question 14

Shapes and polarity of important molecule: Ammonia Molecule–>Trigonal Pyramidal Shape

Answer 14

3 bonding pairs
1 lone pair
Polar molecule
(if polar covalent bonds)

Question 15

Shapes and polarity of important molecule: Carbon Dioxide Molecule 🡪 Linear Shape

Answer 15

2 bonding pairs
no lone pairs
Non-polar molecule (if polar covalent bonds)

Question 16

Shapes and polarity of important molecule: Boron tribromide 🡪 Trigonal Planar

Answer 16

3 bonding pairs
no lone pairs
Non-polar molecule
(if polar covalent bonds)

Question 17

Shapes and polarity of important molecule:Methane Molecule 🡪 Tetrahedral Shape

Answer 17

4 bonding pairs
no lone pairs
Non-polar molecule (if polar covalent bonds