Valence Electrons and Lewis Dot Structures Review Match

Valence Electrons and Lewis Dot Structures

Review: ◦ Match each element on the left with the element on the right that has the most similar chemical properties: Sodium Krypton (Na) (Kr) Phosphorus Neon (Ne) Why did you match the pairs as you did? (P) Potassium Calcium Elements in the same group have the same number of (K) (Ca) valence electrons and therefore similar properties. Magnesium (Mg) Sulfur (S) Silicon (Si) Nitrogen (N) Oxygen (O) Carbon (C)

What are Valence Electrons? ◦ Electrons in the outermost energy level of an atom ◦ Electrons with the highest energy and held loosely

Stability and Valence Electrons ◦ An atom is more stable when it has the maximum number of valence electrons, called a full shell. ◦ Octet Rule: Most atoms want 8 valence electrons to be stable ◦ Be aware there are some exceptions! (Example: Hydrogen & Helium)

Stability and Valence Electrons ◦ Atoms form chemical bonds by losing, gaining, or sharing electrons in order to reach a full set of valence electrons

Lewis Dot Structures (Electron Dot Diagram) ◦ A visual model that shows an element’s valence electrons ◦ Allows us to visualize and predict how elements will combine to form compounds. H

Lewis Dot Structures (Electron Dot Diagram) Process: 1) Write the element symbol. 2) Determine the number of valence electrons 3) Starting at the right, draw dots, counter-clockwise around the element symbol. 4) You have to fill-in each side with one dot before you double up. (Maximum of 2 dots per side) S

Practice