Understanding Lewis Diagrams

What is the octet rule?

• The octet rule states that atoms seek to have eight electrons in their valence shell.

• Atoms prefer to have six electrons in their valence shell.

• Atoms can have any number of electrons without restrictions.

• The octet rule applies only to metals.

How many electrons can the outer shell hold according to the octet rule?

• 8

• 4

• 10

• 6

Draw the Lewis diagram for a water molecule (H2O).

• The Lewis diagram for H2O shows three hydrogen atoms bonded to one oxygen atom with no lone pairs.

• The Lewis diagram for H2O shows an oxygen atom bonded to two hydrogen atoms with two lone pairs of electrons on the oxygen.

• The Lewis diagram for H2O shows two oxygen atoms bonded to one hydrogen atom with no lone pairs.

• The Lewis diagram for H2O shows an oxygen atom with four hydrogen atoms and one lone pair of electrons.

What is the purpose of a Lewis diagram?

• To show the molecular weight of a compound.

• To determine the color of a chemical reaction.

• The purpose of a Lewis diagram is to illustrate the arrangement of valence electrons in a molecule.

• To predict the boiling point of a substance.

Give an example of an element that follows the octet rule.

• Hydrogen (H)

• Carbon (C)

• Neon (Ne)

• Oxygen (O)

Draw the Lewis diagram for carbon dioxide (CO2).

• The Lewis diagram for CO2 shows a carbon atom in the center with double bonds to two oxygen atoms, each oxygen having two lone pairs.

• The Lewis diagram for CO2 shows a carbon atom with single bonds to two oxygen atoms, each with three lone pairs.

• The Lewis diagram for CO2 features a carbon atom surrounded by four oxygen atoms, each with one lone pair.

• The Lewis diagram for CO2 has a carbon atom with triple bonds to two oxygen atoms, with no lone pairs on the oxygens.

What happens to atoms that do not have a full outer shell?

• Atoms will lose their electrons if they lack a full outer shell.

• Atoms with full outer shells are unstable.

• Atoms that do not have a full outer shell will react with other atoms to achieve a stable electron configuration.

• Atoms with incomplete outer shells do not interact with others.

Which elements are most likely to form covalent bonds?

• Alkali metals like sodium and potassium

• Noble gases such as helium and neon

• Nonmetals such as carbon, nitrogen, oxygen, and halogens.

• Metals like iron and copper

Draw the Lewis diagram for a sodium chloride (NaCl) compound.

• Na+ [Cl-]

• NaCl2

• Na- [Cl+]

• Na+ Cl-

Why is it important to understand Lewis diagrams in chemistry?

• They are not relevant to chemical reactions.

• They provide information about molecular weight.

• It is important to understand Lewis diagrams because they illustrate electron arrangements and bonding in molecules, aiding in predicting chemical behavior.

• They are only useful for drawing chemical structures.