Earth's Changing Surface: Weathering and Erosion

This class typically lasts the entire 50 minutes, but depending on class size and students' interest in verbal participation, the class may be slightly shorter. 

During this class, students will be interacting with each other and the teacher through video and audio. Chat is available for answers but is not necessary. Discussion is encouraged throughout the lesson.
 
The lesson will begin with the teacher doing a visually accessible demonstration on a separate camera. During the demonstration, students will get to see two rock minerals, calcite and halite, ground down, and students will be encouraged to hypothesize what might happen if vinegar, which will be representing rain, is stirred into the minerals. I will be discussing with students during the demonstration to help guide their discovery of rain's affect on minerals in rock. Once the demonstration is complete, students will observe what occurred to the two minerals once the acidic material was added, and we will use these observations to begin our discussion of weathering and erosion. 

This period of exploration will be followed with a short but thorough description of what weathering is, first introducing mechanical weathering and then chemical. We will revisit our findings from the previous demonstration to determine if the weathering that took place was of a chemical or mechanical nature, as well as looking through several images and allowing the students to decide and share with the class what form of weathering is taking place to change the features of earth in each image. During this time of learning or review, depending on your child's previous experience with the topic, students will have an opportunity to carry out two very simple demonstrations on their own to show specifically what physical and chemical weathering is. 
Next, I will introduce the concept of erosion, giving sufficient information to make it clear how erosion is a compliment to weathering but is a different process from weathering. We will look at images as I point out how erosion helps shape mountains, create canyons, and in general change the surface of the Earth. Students will add on to one of there previous weathering demonstrations by carrying out the process of erosion on their final physical weathering product. We will then take a special look at two mountain ranges over one billion years old and compare them to the newest mountain range. We will use our new weathering and erosion terms and concepts to decide why the mountain ranges look so different. 

We will finish the lesson with a simple review and check of information. As a finale, students will be given an opportunity to think critically about whether a marble statue would last longer in a dry desert region or in a moist region. 
After thought and discussion, I will show the students two images--one of Cleopatra's Needle in NY, a gift from the Egyptians, and The Obelisk of Ramesses II. These two statues have existed since ancient times, and when Cleopatra's Needle was sent to NY it was in fairly identical shape to the Obelisk. However, the way the two have held up since then have been drastically different. 

Other images may be shown and discussed throughout the lesson depending on time and need.