We began the week with Lesson 6, the first lesson Chapter 2. Students were introduced to the language of chemistry, learning how chemical formulas for compounds are written as collections of elements. The Lesson 6 PowerPoint defines several important vocabulary terms and prepared students for the lab activity (Lesson 6 worksheet). For the lab, there 18 different solid and liquid elements and compounds for students to observe (different from those pre-filled on the worksheet). The observations consumed the remainder of the class period, and students were asked to read Lesson 6 in the textbook in preparation for completing the lesson tomorrow during class.
Daily Archives: September 21, 2015
Cells & Homeostasis: Egg Lab Procedure Writing
Class began with students receiving their graded quizzes from Friday. We reviewed the correct responses and students learned that their lowest quiz score will be dropped each quarter. Make-up quizzes are not available, so student attendance on Fridays is very important. Students also learned about the weekly extra credit opportunity: read a scientific article (available in the classroom magazine collection or online) and write a paragraph explaining what was learned. The article must be related to the content covered in the most recent quiz, and the paragraph must be turned in prior to the next quiz in order to qualify for five extra credit points.
After the quiz review, we turned to the Egg Lab. In their lab notebooks, students wrote the steps of the procedure they followed on Friday to measure the starting mass of their eggs and immerse the eggs in vinegar to begin the process of dissolving the eggshell. Next, students made visual observations of their eggs before putting on gloves and handling their eggs while rinsing them. Eggs were then placed back in the cups with fresh vinegar, recovered with plastic wrap, and returned to the fume hood for another day. Students were encouraged to bring a school-appropriate liquid tomorrow as we continue our study of how cells interact with their environment by moving molecules across the cell membrane.
Egg Lab Procedure:
- Write name and class period on a cup with a Sharpie.
- Measure the mass of one egg with a scale while wearing gloves. This is the starting mass in grams.
- Place the egg in the cup and record the starting mass on the cup.
- Pour vinegar over the egg until it is completely covered.
- Cover the cup in plastic wrap.
- Place the cup inside a fume hood for three days.
- Wearing gloves, observe the egg and record observations.
- Gently pour vinegar solution into sink, carefully catching egg.
- Rinse egg and cup gently with room temperature tap water.
- Return egg to cup and repeat steps 4-5.
- Place the cup inside a fume hood for one more day.