Lesson 78 provided students with additional practice converting from mass to moles and from moles to mass. The Lesson 78 PowerPoint ChemCatalyst activity asked students to predict whether arsenic (As), arsenic oxide (As2O3), or arsenic sulfide (As2S3) was most toxic. Students had to consider how many atoms of arsenic are in each molecule, and which has more molecules in a fixed mass. Some of the work from the entry task is shown below:
For the Lesson 78 Worksheet, students worked in pairs to complete the questions. For homework, students were assigned questions 5-8 from the textbook.
We began class with an entry task asking students to ponder: where do trees get their mass from? Students had some time to think about the question and write or draw pictures describing their ideas. Selected students or small groups of students were asked to share their ideas publicly on the class white boards (pictures below). The ideas were labeled as possible hypothesis statements. Students then had to select the hypothesis they believed to be the most correct and then wrote a conclusive statement explaining their understanding of the science behind the hypothesis statement.
We followed that with a video:
After the video, students received the first draft of their conclusions back for more focused editing. Slides 3 and 4 of the attached slide deck helped the students focus their scientific writing on clearly articulating the claim, evidence, and reasoning for their revised conclusion.