A two-dimensional diagram that represents the arrangement of valence electrons around atoms in a molecule, showing bonding pairs as lines between atoms and non-bonding (lone) pairs as dots.
A map showing how electrons are arranged and shared between atoms.
Showing a random 20 of 50 problems.
Example 1
easy
In a completed Lewis structure, how many electrons satisfy the octet of a non-hydrogen atom?
Example 2
easy
Draw the Lewis structure for water (H2O).H₂O: 2 lone pairs on oxygen give water its bent shape
Example 3
easy
In a Lewis structure for CH4, how many bonding pairs surround carbon?
Example 4
easy
How many valence electrons does the polyatomic ion NH4+ have to distribute?
Example 5
easy
How many valence electrons does a single oxygen atom (group 16) have?
Example 6
medium
How many total valence electrons are needed to draw the Lewis structure of CO32−?
Example 7
easy
In a Lewis structure, a double bond represents how many shared electrons?
Example 8
hard
Which atom is conventionally chosen as central in a Lewis structure: the most or the least electronegative?
Example 9
medium
For CH4, verify carbon's octet: how many electrons surround carbon in the Lewis structure?CH₄: four C–H bonds — how many electrons surround carbon?
Example 10
hard
How many resonance structures does the nitrate ion NO3− have, equivalent by symmetry?
Example 11
medium
How many lone pairs total are in the Lewis structure of F2?
Example 12
medium
How many lone pairs are on each oxygen atom in the Lewis structure of CO2?
Example 13
medium
How many bonding electrons are in the triple bond of N2?
Example 14
medium
Calculate the formal charge on nitrogen in the Lewis structure of NH3.
Example 15
hard
Draw the Lewis structure for the nitrate ion (NO3−). Include formal charges.NO₃⁻: trigonal planar, one resonance structure shown (N formal charge +1)
Example 16
medium
Draw the Lewis structure for ammonia (NH3), and state how many lone pairs are on the nitrogen atom.NH₃: three N–H bonds, 1 lone pair on nitrogen
Example 17
medium
Draw the Lewis structure for carbon dioxide (CO2).
Example 18
challenge
In the carbonate ion CO32−, how many equivalent resonance structures place the single C=O double bond?
Example 19
medium
How many lone pairs surround the central atom in H2S?H₂S: sulfur mirrors oxygen in water — how many lone pairs on S?
Example 20
easy
How many lone pairs are on the oxygen atom in a water H2O Lewis structure?H₂O: oxygen has 6 valence electrons; after 2 bonds, how many lone pairs remain?