Minerals In Toothpaste (Part 1/2)
Lesson 3 of 8
Objective: SWBAT learn about the uses of various minerals in toothpaste.
Bell Ringer - Ground Rules
Before viewing the video: Mining Right for a Sustainable Future Ground Rules: "Mining and the Modern World," Chapter 3 I ask, "Can you name a mineral used in toothpaste?" I give students a minute to think about this and then look for responses. At this point, not many students are familiar with minerals in toothpaste. I thought it appropriate to study the minerals found in toothpaste because everyone uses toothpaste (at least I hope so!), can easily relate to it, and students can talk about toothpaste with their family.
Next, I pass around a variety of tubes of toothpaste and ask students to look for the active ingredient list on the toothpaste box. I make a list on the chalkboard including writing any repeat answers - we're looking for patterns. (Optional: You can also use the SMARTBoard or document camera). After we have a list, I ask students to identify which ingredients are most common among the different brands. Student reactions were varied but most students noted that they did not know there were minerals in toothpaste! Students learned that minerals are in toothpaste and also in everyday things like metals in the kitchen. They learned that minerals play a big part in everyday life. Students being to (SP#6) construct explanations of phenomena.
During the video:
Ask students to record in their Science Journal (Notebook), a list of the minerals shown in the video.
After viewing the video:
I ask students to share their list with their partner, then we share a list of minerals as a class. I write this list on the chalkboard, SMARTBoard, or Document Camera.
Next, we discuss the minerals found in toothpaste and then check for student understanding that every brand of toothpaste contains a slightly different mixture of minerals. Point out that all toothpaste contains abrasive minerals to rub the plaque away. The most common abrasive minerals used in toothpaste include silica, limestone and calcium carbonate. Most toothpaste brands also contain the mineral fluorite, which is composed of calcium fluoride. This mineral makes the tooth more resistant to decay. Sodium carbonate is used in some toothpastes to whiten teeth. Zinc is sometimes used in toothpastes as an anti-bacterial agent to prevent gingivitis (gum disease).
Toothpastes may also contain other minerals and ingredients to make the toothpaste sparkly (mica), to make it white (titanium), to make it thick (sand), to whiten teeth (sodium carbonate) and to fight bacteria (zinc).
Uses of Minerals
To discuss the common minerals found in toothpaste, I show the Minerals in Toothpaste Presentation. I explain the common minerals found in toothpaste, the types of rocks where they are found, and where they are mined. This information helps build background knowledge, helps student understanding about each type of mineral, and helps students understand how minerals are important in our everyday lives.
I ask students to create a foldable for their notes and pictures, including each mineral (fluorite, mica, sand, and sodium carbonate). Students cut and fold, then glue the Foldable into their Science Journal (Notebook).
I provide a tray with samples of each mineral for every group of students. As I show the Minerals in Toothpaste Presentation, I discuss each mineral in more detail. After discussing each mineral, I ask students to make observations about that mineral and write in their Foldable. A tray of examples of minerals makes the experience authentic and real. Students like touching, observing, and looking closely at these minerals.
This lesson focuses on NGSS Cross Cutting Concept #1 Patterns which states that patterns in the natural world can be observed and students will observe patterns in matter. Also, NGSS Cross Cutting Concept #6 Structure & Function which states that the way in which an object is shaped and its substructure determine it properties and function. These Cross Cutting Concepts are important for students to develop and make connections as they observe the physical properties of minerals.
Additionally, this lesson will guide students as they work towards mastery of the standard Earth Science Standard MS-ESS 3-3 which states that students will apply the scientific principles to design a method for monitoring and minimizing a human impact on the environment (mining).
Note: I want to give credit for this lesson to the Caterpillar company, which builds heavy equipment used in mining (and many other industrial products). They have an educational section on their website that is a free, reliable, easily accessible resource.
What Did You Learn?
The most important thing I learned today was . . .
I would like to learn about . . .
I ask students to reflect on the lesson by having them complete an Exit Slip which uses two (2) sentence frames. Sentence frames provide the start of a complete sentence. This makes the writing more rigorous and is especially helpful for Special Education and ELL students.
I want students to write quietly for 2 - 3 minutes. As part of a school wide writing goal, I remind students to use TCA's (Target Correction Areas) such as a capital letter, correct end punctuation, and a complete sentence.
This formative assessment strategy will provide feedback to guide my future instruction. Writing is thinking, and by helping them with sentence frames I've pushed the cognitive load onto selecting the specific words and thoughts that they will need to complete these sentences. It's important to give students a few minutes to process their thoughts and write their response. It's best practice.