Covalent Bonding
Covalent bonds share electron pairs.
About this topic
A covalent bond forms when two atoms share a pair of electrons, usually between non-metals, so that each achieves a full outer shell. A single bond shares one pair, a double bond two pairs and a triple bond three pairs, with each additional pair making the bond stronger and shorter.
The shared pair is attracted to both nuclei at once, which holds the atoms together. In hydrogen, H2, each atom contributes one electron to give both a full first shell. In oxygen, O2, two pairs are shared (a double bond), and in nitrogen, N2, three pairs, which makes nitrogen gas very unreactive. Sharing may be equal or unequal depending on electronegativity. A lone pair is an outer pair not used in bonding. In a coordinate or dative bond, both electrons come from one atom, as in the ammonium ion.
Covalent bonding builds water, carbon dioxide, sugars, proteins, DNA and plastics, so it is the basis of life and many materials. Molecules held by these bonds often have low melting points because only weak forces act between molecules.
A common mistake is thinking covalent bonds are weak; the bonds within a molecule are strong, but the forces between molecules are weak. Another is forgetting that hydrogen needs only two electrons, not eight.
Key ideas
- Between non-metals
- Single, double, triple bonds
- Form molecules
Quick check
Use cases: where Covalent Bonding helps
- Homework: review the key idea behind Covalent Bonding before you start a problem set.
- Exam revision: use the quick check to test whether you can recall Covalent Bonding without notes.
- Visual learning: play with the interactive lab to see how Covalent Bonding changes when you adjust its inputs.
- Teaching a friend: explain Covalent Bonding in your own words, then compare your version with the key ideas.
Chemistry explains medicine, food, cleaning products, fuels and building materials.
Frequently asked questions
What is Covalent Bonding?
Covalent bonds share electron pairs.
What will I learn in Covalent Bonding?
Between non-metals. Single, double, triple bonds. Form molecules.
Is Covalent Bonding part of Chemistry?
Yes. It is one of 150 Chemistry topics on LearnViz HighSchoolEdu, with 3 key ideas, a live animation and a quick check.
Does the Covalent Bonding lab work on a phone or tablet?
Yes. The animation resizes to fit your screen and supports touch, so you can drag, tap and slide with your finger.
How should I study Covalent Bonding?
Read the summary and key ideas first, play with the interactive lab to see the idea in motion, then answer the quick check. If you get a question wrong, go back to the key idea it tests.
Do I need an account, and is my progress saved?
No account is needed. Marking a topic as learned is saved in your own browser, so it stays on that device and is not sent to a server.