Density

Science Lesson Plan

Grade Level: 5th

Area: Physical Science- Density

Objectives:

Students will prepare litmus strips from red cabbage juice. With their strips they will test 5 household liquids for the color change the liquid produces on the indicator strip. Students will combine these results into a class chart.

Materials:

Small red cabbage, coffee filters water, baggies, lemon juice, baking soda

Set:

Today we are going to make indicator strips out of red cabbage juice. Once

these strips are dried, we will test different solutions and their

reactions with the test strips. These reactions will help us determine the

pH of a solution. We will then compare the reactions to a pH chart

provided. First, let's get our indicator strips ready.

Procedure:

To make indicator strips, tear small (very small) pieces of red cabbage and put into baggie. Crush with a rolling pin. Add a small amount ( 1 or 2 tbsps) of water and mix thoroughly. Next, take a paper coffee filter that has been cut into strips and place in cabbage and juice baggie. Thoroughly wet the strip and then lay out to dry on wax paper. Make sure the indicator strip is dry before sing to test your solution. The juice may be filtered by cutting a small corner off the baggie and allowing the juice to drain into a cup.

We will start with a lemon. Squeeze a small amount of lemon juice into a dish. Observe its color and take a whiff by moving the liquid out from of your face but at about nose level. Record your observations. Now, dip an end of your indicator strip in the lemon juice. Let dry. The strip should have turned red-to-pink indicating a very high acid. If we look on the pH chart you will see the color red is 1 on the pH scale. The pH scale runs from 1 to 13. Around 7 is neutral and anything above 7 is considered a base. A number above 7 is generally considered a base and a number less than 7 is considered to be an acid. Let's try water. What did you get? You should get o change since the water is neither an acid or base. Let's do one more together. Mix 1 tbsp baking soda with ј cup water. Dip an end of another indicator strip in the water. What are the results? Green, is about 10 or 11. Baking soda is considered a base.

Now I want you to take some of your indicators strips home today. Find 5 liquids around you home that you can test. Record the color when you put the end of your indicator strip in each solution. Bring your results back to class tomorrow. You may need to ask your parents with assistance with some or the liquids.

Ex: Coke Milk Broth when a vegetable is cooked Vegetable oil nail polish remover apple juice tomato juice.

Closure:

1.Ask what a base/acid may produce ?

2.give a color and ask whether is acid/base

Assessment:

Assess students understanding by listening to their responses during closure and discussion period. In addition, assess students understanding and retention of the concept by reviewing data colleted from test done at home.

Grade Level : 2nd and up

Area: Physical Science- density

Objectives:

1. The class will explain the concept of density.

2. The class will predict and record what liquids will sink and float.

3. The class will c ompare the densities of several liquids

4. The class will explain why the liquids used in the experiment stacked on top of each other in the order observed

Materials: