Title: Understanding Atomic Mass

Grade Level: 5th Grade

Objective: Students will be able to understand the concept of atomic mass and how it is calculated.

Materials: - Periodic table - Whiteboard and markers - Worksheets - Calculator

Introduction (10 minutes): 1. Begin the lesson by asking students if they have ever heard of the term “atomic mass”. 2. Explain that atomic mass is the mass of an atom of a chemical element, expressed in atomic mass units (amu). 3. Show them the periodic table and explain that each element has a unique atomic mass. 4. Ask students if they know how atomic mass is calculated.

Body (30 minutes): 1. Divide the class into groups of 3-4 students. 2. Distribute worksheets to each group. 3. Ask students to look at the periodic table and find the atomic mass of three different elements. 4. Instruct them to write down the atomic mass of each element on the worksheet. 5. Ask students to add the atomic masses of the three elements and write down the total. 6. Explain that this is how atomic mass is calculated - by adding the masses of the protons and neutrons in the nucleus of an atom. 7. Ask students to calculate the atomic mass of one more element on their own and write it down on the worksheet. 8. Have each group share their answers with the class and discuss any discrepancies. 9. Use the whiteboard to demonstrate how to calculate atomic mass using the example of carbon (atomic number 6, atomic mass 12.01). 10. Ask students to calculate the atomic mass of one more element as a class.

Conclusion (10 minutes): 1. Review the concept of atomic mass and how it is calculated. 2. Ask students to share one thing they learned about atomic mass. 3. Collect the worksheets and review them to assess student understanding. 4. End the lesson by reminding students that atomic mass is an important concept in chemistry and that they will continue to learn more about it in the future.