IMF - Polarity

polar adjective

1. relating to the North or South Pole. "the polar regions"

2. PHYSICS•CHEMISTRY having electrical or magnetic polarity.

polarity noun

• the property of having poles or being polar.
  "it exhibits polarity when presented to a magnetic needle"

  • the relative orientation of poles; the direction of a magnetic or electric field.
    plural noun: polarities
    "the magnetic field peaks in strength immediately after switching polarity"

1. Khalid: Okay, so I get that intermolecular bonds are important, but what about those intramolecular bonds Mr. Collins was talking about? Are they the same thing?

2. Fatima: No, they're different. Intramolecular bonds are the forces holding atoms together within a molecule. They're much stronger than intermolecular bonds. Think about it – it takes a lot of energy to actually break apart a water molecule, but it's much easier to separate water molecules from each other, like when water evaporates.

3. Ayah: Right! And Mr. Collins said that the strength of an intramolecular bond depends on the electronegativity difference between the atoms. It's like a tug-of-war for the electrons in the bond.

4. Khalid: Electronegativity... that's how much an atom wants to hog the electrons, right? So, like, in a water molecule, oxygen is more electronegative than hydrogen, so it pulls the shared electrons closer to itself.

5. Fatima: Exactly! That creates a polar covalent bond, where the oxygen has a partial negative charge and the hydrogens have partial positive charges. It's like the electrons spend more time hanging out around the oxygen atom.

6. Ayah: But what about molecules where the atoms have similar electronegativities? Like, if they're both equally strong in the electron tug-of-war?

7. Khalid: Then you get a nonpolar covalent bond, where the electrons are shared more equally. Mr. Collins gave the example of diatomic molecules like oxygen (O₂) or chlorine (Cl₂). The atoms have the same electronegativity, so there's no separation of charge. It's a fair sharing arrangement.

8. Fatima: So, the type of intramolecular bond affects how the molecule interacts with other molecules? Like, polar molecules are attracted to each other because of those partial charges?

9. Khalid: Exactly! And that's why water is such a good solvent. Its polar molecules can interact with other polar molecules and ions, forming solutions. Think about how salt dissolves in water – the positive sodium ions are attracted to the partially negative oxygen atoms in water, and the negative chloride ions are attracted to the partially positive hydrogen atoms.

10. Ayah: But nonpolar molecules don't have those strong attractions, so they tend to stick to themselves. That's why oil and water don't mix – the nonpolar oil molecules are more attracted to each other than to the polar water molecules. They just don't "speak the same language" in terms of charges.

11. Fatima: This is all starting to make more sense now. So, both intermolecular and intramolecular forces play a role in determining the properties of a substance. It's like a complex dance of forces, with different types of bonds influencing how molecules interact with each other.

12. Khalid: Yeah, and it's amazing to think that these tiny forces, that we can't even see, are responsible for so much of what we observe in the world around us.