General chemistryLesson 2 of 6 in the course Chemical Bonding and Molecular Geometry

Covalent Bonds: Energy, Polarity, and Electronegativity

5 flashcards · 5 quiz questions · 5 match pairs · 5 fill-in sentences · English

Save course
Lesson progress
0 / 5

Your progress is kept in this browser only.Sign up to save it

Summary

An ionic bond results from electrostatic attraction between oppositely charged ions, commonly formed when electrons transfer from a metal to a nonmetal. A covalent bond forms when atoms are mutually attracted to a shared pair of electrons. Covalent bonds commonly form between nonmetal atoms, which have similar tendencies to attract electrons.

For example, two hydrogen atoms share their electrons to form an H₂ molecule. The shared electrons are attracted to both nuclei. Each hydrogen atom is thereby associated with two electrons, giving it the stable electron arrangement of helium.

All flashcards

What is a covalent bond?
A covalent bond is the mutual attraction of atoms for a shared pair of electrons.
Why does H₂ formation stabilize two hydrogen atoms?
Each shared electron is attracted to both nuclei, and each hydrogen atom is associated with two electrons, like helium.
What is bond length?
It is the distance between the bonded atoms' nuclei at which the system's potential energy is lowest.
How do energy changes differ for bond formation and bond breaking?
Bond formation releases energy and is exothermic; bond breaking requires energy and is endothermic.
Why are covalent molecular substances often poor electrical conductors?
They generally lack freely moving charged particles that can carry an electric current.

Quiz questions

  1. What does electron affinity describe?Answer: The energy change when an isolated gas-phase atom gains an electron.
  2. How does electronegativity generally change across the periodic table?Answer: It increases from left to right across a period and decreases down a group.
  3. In potassium nitrate, KNO₃, what types of bonding are present?Answer: Covalent bonds within NO₃⁻ and ionic attraction between K⁺ and NO₃⁻.
  4. A hydrogen–fluorine bond has an electronegativity difference of 1.9. How is it classified?Answer: Polar covalent.
  5. If two bonded atoms have electronegativities of 3.0 and 2.1, what is their absolute electronegativity difference, 4EN4 EN?Answer: 0.90.9

Based on Chemistry 2e by Paul Flowers, Klaus Theopold, Richard Langley, William R. Robinson, PhD (OpenStax), licensed CC BY 4.0. Adapted into a summary, flashcards and quizzes.

More in General chemistry

All General chemistry lessons
General chemistryCrystal Structures: Lattices, Ionic Solids, and X-Ray Diffraction5 flashcards · 5 quiz questions · 4 gamesPlay free →General chemistryChemical Equations: Balancing, State Symbols, and Ionic Equations5 flashcards · 5 quiz questions · 4 gamesPlay free →General chemistryOxidation Numbers and Redox Half-Reaction Balancing5 flashcards · 5 quiz questions · 4 gamesPlay free →General chemistryMatter, Atomic Structure, Isotopes, and Chemical Bonding5 flashcards · 5 quiz questions · 4 gamesPlay free →General chemistryStoichiometry: Balancing, Yield, Gas Relations, and Reaction Networks5 flashcards · 5 quiz questions · 4 gamesPlay free →General chemistryPeriodic Trends in Atomic Size, Ionization Energy, Electron Affinity, and Metallic Character5 flashcards · 5 quiz questions · 4 gamesPlay free →