The idea
Two non-metals cannot both give electrons away — neither wants to. Instead they share, forming a covalent bond and a discrete molecule.
| Ionic | Molecular | |
|---|---|---|
| Made of | Metal + non-metal | Non-metal + non-metal |
| Electrons are | Transferred | Shared |
| Melting point | High | Usually low |
| Conducts when dissolved | Yes | Usually no |
| Basic unit | A repeating lattice | A single molecule |
Naming with prefixes
Molecular names use prefixes; ionic names do not.
| Prefix | Number |
|---|---|
| mono- | 1 |
| di- | 2 |
| tri- | 3 |
| tetra- | 4 |
| penta- | 5 |
- — carbon monoxide
- — carbon dioxide
- — dinitrogen tetroxide
One letter, one very large difference
Carbon dioxide is what you exhale. Carbon monoxide binds to your blood 200 times more readily than oxygen does and will kill you in a closed garage. The difference is a single oxygen atom — which is precisely why chemical names are so fussy.
Curriculum connection
C2.7
describe the relationship between the structure of simple compounds and their chemical formulas
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C1.1
assess social, environmental, and economic impacts of processes associated with the life cycle of consumer products, considering the elements and compounds used to make them, and suggest ways to enhance positive impacts and/or minimize negative impacts
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