Lewis Diagrams

Q: What is a Lewis structure?

A: A diagram showing the valence electrons, bonding pairs, and lone pairs in a molecule or polyatomic ion.

Q: What are valence electrons?

A: Electrons in the outermost shell of an atom that are involved in bonding.

Q: What is a bonding pair?

A: A pair of electrons shared between two atoms, forming a covalent bond.

Q: What is a lone pair?

A: A pair of valence electrons located on one atom that is not involved in bonding.

Q: What is the octet rule?

A: Many atoms form bonds to achieve eight electrons in their valence shell. Hydrogen is an exception because it is stable with two electrons.

Q: How do you draw a Lewis structure?

A: Count total valence electrons, arrange the atoms, draw single bonds, complete outer shells, place remaining electrons on the central atom, and form multiple bonds if needed.

Q: How do you draw a Lewis structure for a negative ion?

A: Add electrons equal to the negative charge before completing the structure.

Q: How do you draw a Lewis structure for a positive ion?

A: Subtract electrons equal to the positive charge before completing the structure.

Q: What is a coordinate covalent bond?

A: A covalent bond in which both shared electrons are donated by the same atom.

Exam reminder: You need to be able to draw Lewis structures for molecules and polyatomic ions, including structures with multiple bonds.