Unit 2: Atomic Structure

In this unit, the focus will be on understanding the differences between atoms and the calculation of atomic masses. The focus will also be on the review of early models of the atom, subatomic particles, atomic and mass numbers. This unit will also focus will be on measuring chemical quantities involving Avogardo's number, molar mass, and molar volume, as well as calculating percent composition and determining empirical and molecular formulas.

Enduring Understandings

Students will understand that:

• the mole is a counting unit and can be represented as a conversion factor
• chemical substances can be measured by counting particles, determining mass, and determining volume
• the mass of one mole of an element is equivalent to its atomic mass
• percent composition refers to the relative size of parts that make up 100 percent of something
• empirical and molecular formulas are determined from chemical quantities

Essential Questions

• Why is the mole used as a counting unit?
• How can quantities of chemical substances be measured?
• How are molar mass and atomic mass different?
• How is percent composition used to analyze a chemical substance?
• How does the molecular formula of a compound compare withthe empirical formula?