Lewis Structure Practice

Ionic Lewis Structures

• Metal and Nonmetal• First determine the chemical formula if it is

not given to you.• Draw the Lewis structure for each atom• Draw arrows showing electrons transferring

from cation to anion• Redraw the ions using brackets.

Ionic Lewis Structure Practice!

• 1. Magnesium Bromide

• 3. Aluminum Oxide

• 2. Li2S

• 4. NaF

Covalent Lewis Structures

• Write the symbols in correct arrangement (no dots yet!)– HINTS: Place least electronegative element in

middle. Usually form more than 1 bond. Usually the first element listed

– Hydrogen and Halogen atoms often only bond to one other atom and are usually on outside

– Carbons usually bond to each other– Formula for complex molecules are often written

out in a way that hints at its structure.

Covalent Lewis Structures

• Determine the total number of valence electrons

• Use 2 valence electrons to form a bond between each atom

• Place remaining electrons in pairs until there are 8 electrons around each atom (2 for H) or all electrons have been used– Extra electrons go on central atom– Atoms in 3rd period and beyond can have more

than 8 electrons around them

Covalent Lewis Structures

• If not enough electrons are available to give all atoms an octet, look for double bonds and triple bonds!

• Double check your work!!