Physical Science / Unit 4: Chemical Bonds and Compounds
4.3 Covalent Bonds
Notes
A covalent bond forms when atoms share electrons, usually between nonmetals.
- A group of atoms joined by covalent bonds is a molecule.
- Single bond: 1 shared pair (H-H). Double bond: 2 shared pairs (O=O). Triple bond: 3 shared pairs (N≡N).
- In water, oxygen shares one pair with each of two hydrogen atoms.
- Sharing can be unequal, making a polar bond (as in water); equal sharing is nonpolar.
- Covalent compounds generally have lower melting points than ionic compounds and do not conduct electricity well.
Practice
A covalent bond is formed when atoms:
Sharing electrons is the key feature of a covalent bond.
Which pair of elements will most likely form a covalent bond?
Two nonmetals share electrons.
A nitrogen molecule has a triple bond. How many electrons are shared between the two nitrogen atoms?
A triple bond is three shared pairs, or 6 electrons.
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