Electron Dot Structure
- Devised by chemist Gilbert Lewis
- Ignores core electrons and focuses on valence electrons
- Diagrams that show valence electrons in the atoms of an element as a dots
Valence Electrons
- The electrons in the highest occupied energy level of an element’s atoms
- Largely determines the chemical properties of an element
- Usually only involved in chemical bonds
The Octet Rule
- Used by Gilbert Lewis to explain why atoms form certain kinds of ions and molecules
- States that in forming ionic compounds, atoms tend to achieve the electron configuration of a noble gas
- Turing into noble gas—> made more stable
How do cations form?
- Produced by the loss of valence electrons from metal atoms
- Cations form in metals
Transition Metal Configurations
-Transition metals are an exception to the octet rule because they don’t have noble gas configurations
How Anions form?
- Anions are produced when an atom gains one or more electrons
- Anions form in nonmetals
- The name of anions end in -ide
Compound
- Two or more different types of atoms bound together
- Also a type of molecule
Molecule
-Two or more atoms bonded together
Ionic Compound
- A compound composed of cations and anions
- Anions and anions do not join together
- Cations and cations do not join together
- Electrically neutral
- Have high melting points
- Usually form as salts
- Can conduct electricity when melted or dissolved in water
Ionic bonds
-The electrostatic forces that hold ions together in ionic compounds
Do metalloids form ionic compounds?
-No
Two ways to represent an ionic compound
- Chemical formula (ex: NaCl, CaCl2)
- Written name (ex: Sodium Chloride, Calcium Chloride)
What do the names of ionic compounds tell you?
- The charge of the anion and cation
- How many of each type of atom are present in the compound
Polyatomic Ion
-Group of charged atoms that are covalently bonded together and can be considered to be acting as a unit
