Drawing Lewis Dot-Diagrams

Dot Diagram of a single Atom. Write the element’s Symbol and imagine there is a box drawn around it. Find the element’s GROUP Number on the periodic table. (This equals the atom’s number of Valence Electrons) Place the first dot on the bottom side of the imaginary box. Moving clockwise around the box, place the next dot on the next side. Continue this process until all dots have been placed.

Rules for Dot-Diagrams Maximum number of Dots around and element: Hydrogen & Helium = 2 Everything else = 8 There can only be a max of 2 dots per side of the imaginary box.

Example: Chlorine What group is Cl found? VII A 3 7 Cl 6 4 2 5 1

Example: Bismuth What group is Bi found? V A 3 Bi 4 2 5 1

Dot-Diagrams- Compounds First draw the element with the lowest quantity in the compound Example C2Cl6 ---- Which element would you draw first? Carbon If all elements have the same quantity then draw the one in the largest group first Example CO ----Which element would you draw first? Oxygen

Rules for Compound Dot-diagrams Draw first element Place the next element on a side of the box with only ONE electron. When drawing these “Add On” elements place the first dot in the empty space, then continue in the normal manner clockwise around the new element. It is best to use a different Color for each new element

Cl Example: HCl H What do you draw first? Cl What group is Cl found? VII A Cl H

H H C H H Example: S2CH4 S S The only thing left are the 4 H Now what? What do you draw first? S C What group is C found? Now what? IV A S S C S H H

Example: S2CH4 H H S C S H H