Journal Entry:

 A chemist investigating a sample of lithium found that some lithium atoms have a lower mass than other lithium atoms. The chemist drew models of the two different types of lithium atoms as shown above. 1.What is different about the two atoms?  2.What is the atomic number of each atom?  3.What is the atomic mass of each atom?

Learning Intentions

• We will learn how to describe the structure of an atom

• We will learn what an isotope is and how to write and interpret the symbol for a specific isotope.

Closing Task:

You can write and interpret isotope symbols.

Content Standards being covered:

Students understand the structure of matter at the atomic level and the history that lead to our current understanding.