Electronegativity and bond type | States of matter | High school chemistry | Khan Academy

TL;DR

Electronegativity refers to an atom's power to attract electrons in a molecule, leading to the polarization of covalent bonds.

Transcript

• [Instructor] Electronegativity is probably the most important concept to understand in organic chemistry. We're gonna use a definition that Linus Pauling gives in his book, "The Nature of the Chemical Bond". So Linus Pauling says that electronegativity refers to the power of an atom in a molecule to attract electrons to itself. So if I look at a ... Read More

Key Insights

• ❓ Electronegativity is crucial in understanding the nature of covalent bonds in organic chemistry.
• 💨 The Pauling scale provides a standardized way to compare the electronegativities of different elements.
• ❓ The difference in electronegativity determines the polarity of covalent bonds.
• 🐻‍❄️ A difference in electronegativity greater than 0.5 is generally considered to result in a polar covalent bond.
• ⚖️ Different scales for electronegativity exist, but the relative differences are more important than absolute values.
• 🫀 The movement of electrons in a polar covalent bond results in partial charges on the atoms involved.
• ❓ Nonpolar covalent bonds occur when there is no significant difference in electronegativity.

Questions & Answers

Q: What is electronegativity?

Electronegativity refers to an atom's ability to attract electrons towards itself in a molecule, causing a polarization of the covalent bond.

Q: How is electronegativity measured?

Electronegativity is often measured using the Pauling scale, which assigns numerical values to elements based on their ability to attract electrons.

Q: What happens when there is a difference in electronegativity between two atoms in a molecule?

If there is a difference in electronegativity, the more electronegative atom will attract the electrons closer to itself, resulting in a partial positive charge on the less electronegative atom and a partial negative charge on the more electronegative atom.

Q: How is a polar covalent bond different from a nonpolar covalent bond?

A polar covalent bond occurs when there is a difference in electronegativity between two atoms, causing the electrons to be unequally shared. In a nonpolar covalent bond, the electronegativity difference is negligible, resulting in equal sharing of electrons.

Summary & Key Takeaways

• Electronegativity is the ability of an atom in a molecule to attract electrons towards itself.

• The Pauling scale of electronegativity allows for comparing elements in terms of their electronegativities.

• The difference in electronegativity between atoms determines whether a covalent bond is polar or nonpolar.