The Great Liquid Race-Viscosity

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SWBAT observe the properties of liquids by investigate the flow of liquids during a a liquid race.

Big Idea

It is annoying to get to the end of the ketchup bottom and you have to bang on the table to get the last bit of ketchup. Ketchup is thick and it does not flow like thinner liquids. Why?

Setting the Stage

Next Generation Science Standards:

2-PS1-1- "Matter can be described and classified by its observable properties." In this lesson, students learn that liquids can be thin or thick. The thicker liquids tend to move more slowly due to viscosity. Viscosity is the resistance to flow. This lesson is imperative because students observe various liquids by observing their properties. They are given an opportunity to conduct a race with the liquids to determine which one flows the fastest. This helps them to learn about the thickness of fluid in a fun and creative way as they continue to learn about liquids.

Science and Engineering Practice: 

SP 5 addresses using mathematics and computational thinking. In K-2, students describe, measure, or compare attributes of different objects and display data on charts. In this lesson, the students observe various liquids. They use a chart to record the speed that the liquid travels. This lesson is essential to students because they are going to have the opportunity to observe a science tool (i.e. stop watch) to measure the speed the liquids travel. It is important that students work with tools like scientists.

SP 8 addresses obtaining, evaluating, and communicating information in K–2. Students communicate information with others in oral and written form to discuss scientific ideas.  In this lesson, groups are provided the opportunity to discuss which liquid flows the fastest and why. They discuss how viscosity is the resistance of liquids flowing.

Prior Knowledge:

They understand solids, liquids, and gases are forms of matter. They know solids have a size and shape of its own while liquids and gases do not have a shape or size of its own. They know matter can be describe by properties.

Junior Scientists:

In my class, my students are called Junior Scientists. They wear lab jackets they created early in the school year to be worn during experiments. I call them junior scientists to encourage them to major in Science and Math related careers. I want them to develop a love for Science and Math. Also, we sing "It Is Science Time" or "I Got A Feeling Song" before each lesson.



10 minutes

At their desks, students sing a song at the opening of each science lesson.  This song motivates and engages my Junior Scientists at the beginning of each science lesson. During science lessons, I call my students scientists to empower them and make them dreamers and doers.

“I can” statement

I call on a student to read our "I Can" statement for the day. While using an over-sized microphone, a scientist says, "I investigate the flow of liquids by having a liquid race and I can observe the properties of the liquids." The "I Can" statement helps students take ownership of the lesson as they put standards into context. The other students praise the student that reads the "I Can" statement by clapping.  I encourage students to give each other praise and to boost their self-esteem.



15 minutes

Observing Liquids

At students' desks, I show them 3 liquids (ketchup, oil, and milk). I ask the students what form of matter are these items. The students should respond, liquids. Then I provide the students with their lab sheet for today's lesson. The students are to describe the properties of each liquids. I have students observe the liquids because I want them to describe the properties such as: size, shape, texture, smell, and color. This also sparks students interest before we complete our investigation. Students are invited to share their description of the liquids. Then I ask: Which liquid is thicker?  Then I inform them that viscosity is the resistance to the flow of liquids.

I say, you are going to have a liquid race today. As a whole class experiment, we are going to investigate which liquid flows the fastest. Students are asked to make a predication about the liquids by placing them in order from first-third place. I call on 3 students to release the liquids down the ramp.  I also select a timekeeper. This student times the release by starting and stopping the stopwatch. I help the students as needed. I also select a student to record the data on a chart. The student types in the data on the chart that is displayed on the Promethean Board. Teacher note: The chart is displayed on the Promethean Board.

Once I assign the students a role, I inform the students we are going to test one liquid at a time. For instance, one student releases the oil down the ramp or board. The timer starts the stopwatch when it passes the start line (marked by the teacher). Then they stop the stopwatch when it passes the finish line (marked by the teacher). The person who records type in the data. We complete 3 trials to ensure accuracy. I inform the students that scientist do several trials to ensure accuracy, too. Once all three trails are completed, we calculate the mean. The other two liquids are tested in the same manner.

When the investigation is finished, I pose these questions: In looking at our data, which liquid went the fastest? The milk went the fastest. Why? The liquid was thin. Which liquid went the slowest? The ketchup went the slowest. Why did the liquid go slow? It was thick.  They should respond due to viscosity. How did the liquids travel? In a straight line, fast, or slow. Why did the liquid go in a straight line? It takes the shape of the ramp because liquids do not have a shape.

Liquid Race-Lab Sheet-Student Work

Liquid race-video


10 minutes

While students sit at their desks, they receive an assessment. Depending on students' ability, they write words that describe their learning. In my class, I group my students by abilities. It is my goal for students to perform above grade level. I have a SPA Board (Students Performing Above Grade Level) in my room where students are grouped.  My students get the enrichment or leveled based learning that they need to grow academically.

2 words- Achievers (Below Grade Level)

3 words- Super Stars  (On Grade Level)

5 words- All Stars (Above Grade Level)

The sheet states, What words would you use to describe viscosity? Explain and justify your choices based on the investigation. The assessment is taken up for evaluating.  This assessment helps me to capture what students learned and did not learn while focusing on their abilities. Also, it provides me with data so I can make adjustments on the next lesson if needed.