Unit: Earth’s History
Name of Lesson: Age in Years; Absolute Dating
Taught over 2 blocks:
Grade Level: 9th grade
Subject: Earth Science
Overview and Objective:
Prepared By: A. Danz
Educational Standards Addressed:
Common Core:
Reading Standards for Literacy in Science
and Technical Subjects 6–12
Key Ideas and Detail, grades 9-10
Students will learn about absolute dating
through the method of radioactive dating. It
is required that students are capable of
converting numbers to and from scientific
and standard notation. Fundamentals of
3. Follow precisely a complex multistep
radioactive dating will be expressed through procedure when
notes and applied in a half-life lab
carrying out experiments, taking
measurements, or performing technical
tasks, attending to special cases or
exceptions defined in the text.
Essential Question
Supporting Questions
How do we know the exact date of a fossil or
a rock?
What is a half-life?
Why are only some elements used in
radioactive dating?
What is an isotope?
Physical Science/Earth Science core
curriculum:
Standard 4, Key Idea 1, Performance
Indicator 1.2
j.) Geologic history can be reconstructed by
observing sequences of rock types and
fossils to correlate bedrock at various
locations.
 The regular rate of nuclear decay
(half-life time period) of radioactive
isotopes allows
geologists to determine the absolute
age of materials found in some rocks.
Materials Needed
Note handout, ESRT’s, lab
Assessment
Formal: lab and
worksheet will be
graded
Reflection:
Ask three questions before letting students
go.
How do we know Earth’s exact age?
Informal: checkpoints
throughout notes,
review station activity
packet
1st block:
Do Now
Notes
What is the definition of relative dating?
Take out: ESRT’s
Handout. Students will fill in definitions, use scientific and standard notation,
answer regents questions
M&M Half Life Lab; a model of radioactive decay
Lab
Homework
Work on lab
Reflection
Ask three questions before they leave.
What are the 2 restrictions of Carbon-14? – has to be from something that
was once living, has to be within 50,000 years.
2nd block:
Do Now
What is the definition of absolute dating?
Take out: ESRT’s, notes, lab
Notes
Handout. Students will finish notes specifically work on decay curves
Activity
6 station activity focusing on radioactive dating
Worksheet
Practice questions on radioactive dating.
Lab
Go over questions with M&M Half Life Lab; a model of radioactive decay
Homework
Finish worksheet and lab
Reflection
Ask three questions before they leave.