Page 4: Naming Compounds and Lewis Structures
This page covers naming conventions for compounds and introduces Lewis structures.
Prefixes for Naming Covalent Compounds:
1 - mono, 2 - di, 3 - tri, 4 - tetra, 5 - penta, 6 - hexa, 7 - hepta, 8 - octa, 9 - nona, 10 - deca
Transition Metals:
- Always form cations
- Use Roman numerals to indicate charge in compound names
Example: Iron II chloride is written as Fe2+ Cl-
Highlight: Zinc Zn and Silver Ag are exceptions and do not use Roman numerals, as they only form one type of ion Zn2+andAg+.
Lewis Structures:
Steps to draw Lewis structures:
- Arrange chemical symbols
- Draw correct number of dots onepervalenceelectron around each symbol
- Connect dots with lines to represent bonds
- Continue until all atoms are connected
Note: Not all Lewis structures are perfect, and some atoms may break the octet rule.
VSEPR Theory:
VSEPR ValenceShellElectronPairRepulsion explains the shapes of molecules.
Steps to determine molecular shape:
- Draw Lewis structure
- Count number of electron pairs and atoms attached to the central atom
- Look up shape on a reference handout