SN

Item

Quantity

SN

Item

Quantity

1

Beaker

50

15

Dietary alkali

1 bag

2

Dropper

50

16

Baking soda

1 bag

3

Mortar

10

17

Label

1 bag

4

Glass rod

4

18

Pure milk

1 bottle

5

Spot plate

10

19

Yakult drink

1 pack

6

Juicer

1

20

Green tea drink

1 bottle

7

Sprinkler

4

21

Table salt

1 bottle

8

Purple cabbage

1

22

Grease cleaner

1 bottle

9

Black wolfberry

1 bottle

23

Purified water

3 bottles

10

Rose flower  

1 bag

24

Alcohol

1 bottle

11

Vinegar

1 bottle

25

Soap powder

1 bag

12

Yogurt

2 bottles

26

Effervescent tablet  

1 box

13

Lemon

4

27

Filter paper

1 bag

14

Scissors

10

28

Fine wire

1 bag

Teacher

Students

Before class, the teacher will prepare 60ML violet flower juice as the activity material for the fun experiments.   

As requested by the teacher, students will sit in groups in the activity classroom. 

①Fun experiment: The teacher will reproduce the exploratory experiment of the famous British chemist Robert Boyle--pour 20ML of violet flower juice into each of three small beakers, then add appropriate amounts of purified water, white vinegar and alkaline water respectively into the three beakers, and observe the different color changes in the three beakers. 

[Experimental Observation Table] 

①The teacher will invite students to take the initiative to come up and conduct this fun experiment with the teacher, observe the changes in color, fill out the experimental observation table with the teacher, and think about the causes of these changes. 

②The teacher will encourage students to ask boldly: What questions do you have about the experimental phenomena? 

②Students will actively ask their questions: 

Will the juice of different plants show different colors when mixed with an acid or a base in real life? Why does the juice of certain plants change color when mixed with acidic or alkaline liquid? What is the scientific principle behind the color change of violet flower juice in this fun experiment? 

③With the students' questions, the teacher will usher students into the experimental inquiry. 

Activity Design: 

Students in grades 5 and 6 are generally familiar with acidic substances such as vinegar, but they do not know much about how acidic or alkaline liquid can change the color of plant juice. Therefore, they have a strong desire to dig into this phenomenon. Through a story about scientist's discovery and a fun experiment, the teacher will stimulate students' curiosity and strengthen students' enthusiasm for hands-on inquiry. 

[Experiment 1] Students make the juice of different plants on their own. Based on their real-life experience, students will work together to make the juice of purple cabbage, rose flower, chrysanthemum flower and black wolfberry to enjoy the fun of hands-on practice.   

Teacher

Students

①The teacher will distribute purple cabbage, black wolfberry, rose flower, chrysanthemum flower and other experimental equipment, and ask students to finish the following task: make the juice of different plants. 

①The students will discuss with each other and write down their thoughts of making juice based on real-life experience. 

②The teacher will ask students to share their thoughts of making purple cabbage, black wolfberry, rose and chrysanthemum  juices and provide necessary guidance, thereby obtaining different juice-making methods: 

1. Use a juicer to make purple cabbage juice

Juice the purple cabbage with a juicer. 

2. Use the soaking method to make black wolfberry juice

Put 20 grams of black wolfberry into a beaker and add half a cup of warm water to obtain the black juice. 

3. Make rose and chrysanthemum  juices on their own:

1) Tear rose petals (or chrysanthemum petals) and put them in a mortar to mash; 

2) Add purified water until the petals are just immersed, and leave it for three minutes; 

3) Put a piece of gauze on the mouth of the beaker, pour the mixture onto the gauze to filter and get the juice. 

②Students work in groups to prepare the juice of various plants through different methods. The amount of each juice must be about 50ML, which should be enough for the subsequent experiments. 

③Hands-on practice: making juices.   

[Experiment 2] Students will design a comparative experiment independently to compare the color change of different plant juices in acidic or alkaline solution, and analyze whether all plant juices will show different colors when mixing with acidic or alkaline liquid. 

Teacher

Students

①Dialogue: Please guess which plant juices will change color when mixing with acidic solution or alkali solution? 

①Make conjectures based on real-life experience. 

②The teacher will organize students to independently design a comparative experiment, help them develop a clear experimental plan, and ask them to work in groups to independently explore the color change of different plant juices in acidic or alkaline solution. 

②The students will discuss and compare the experimental plans in groups, develop a clear experimental plan under the guidance of the teacher, undertake the inquiry independently, and record the following on the worksheet:   

③Based on the experimental phenomena, the teacher will introduce the scientific concept of "acid-base indicator" and encourage students to find the acid-base indicator in their self-made juices. 

③After understanding this scientific concept, students will analyze that purple cabbage juice, rose juice and black wolfberry juice can be used as acid-base indicators, while chrysanthemum juice cannot be used as acid-base indicator. 

④Mentioning again the conjectures made by the students before the experiment, the teacher will stress that scientific conclusions still need to be drawn through experiments, and that the truth can only be obtained through practice. 

Activity Design:   

The science classes and real-life experience have allowed students in the upper grades of elementary school master the basic methods of making plant juice. They also know that white vinegar contains acid, but they may have little knowledge of alkaline solutions. By posing questions and engaging in group discussions, students will design a simple exploratory experiment by themselves, and determine the experimental steps under the proper guidance of the teacher, so as to go through the whole processes of empirical inquiry and cultivate teamwork spirit. After the experiment is over, discussion can better help students compare and analyze the experimental results correctly and draw the right conclusions. 

[Story telling] Anthocyanin—a great discovery  

Discussion and sharing: Students will learn how young scientists worked so passionately and diligently, and cultivate the scientific spirit of exploring the unknown. 

Uncover the secret: 

The flower, fruit, stem and leaf of many plants contain pigments, mainly anthocyanin which will show different colors in acidic or alkaline solution. 

Activity Design: 

Students are often interested in the stories of scientists and are more likely to accept new knowledge from such stories. The teacher can use storytelling to help students understand the basic concept of anthocyanin and the characteristic of plant juices changing color when mixing with acidic or alkaline solution. 

①Dialogue: With the self-made acid-base indicator, do you want to learn the acid-base state of some commonly seen substances in daily life? Today, I have brought some commonly seen liquids in daily life. Let's find out whether the things you eat and use every day are acidic or alkaline. First, please guess what are acidic and what are alkaline. 

Students will make conjectures. 

②The teacher will provide materials and organize students to conduct experiments in order to test the acidity or alkalinity of various liquids seen in everyday life. 

Students will conduct experiments in pairs to test the acidity or alkalinity of commonly seen liquids in everyday life, such as soapy water, salt water, pure milk, Yakult drink, Sprite drink, oily cleaner and green tea drink, and record the results on the worksheet. 

③The teacher will organize students to share the experimental results. 

Students will share their experimental results in groups. For example, salt water is neither acidic nor alkaline; soapy water, green tea drink and oily cleaner are alkaline; and Yakult drink and Sprite drink are acidic. 

Activity Design: 

From the previous experiments, the students have already known the phenomenon of plant juices changing color when mixing with acidic or alkali solution, so they have mastered the method to test the acidity or alkalinity of the substance to be tested. The teacher can ask students to use the self-made acid-base indicator to test the acidity or alkalinity of substances commonly seen in everyday life, so as to help them experience the sense of achievement from learning and cultivate the scientific spirit of seeking truth from practice. 

①Dialogue: Through the previous independent inquiry activities, I believe everyone can now become a magician. Now, every two students will form a group to make a flower that will change its color, so as to complete our "Seven-Color Flower" project. 

The teacher will distribute roses made with filter paper and encourage students to add color by themselves. 

Every two students will work with each other to make a personalized "Seven-Color Flower", and actively go to the stage to do the "Seven-Color Flower" magic show for the teacher and other students. 

②The teacher will distribute the student questionnaires and ask students to rate themselves honestly based on the knowledge learned and the experiments conducted. 

Through the teacher questionnaire, the teacher will rate students fairly based on their hands-on skills and knowledge mastery. 

Both the teacher and the students will complete the questionnaires. 

Acidity

Alkalinity

White vinegar

Alkali solution

Rose juice

Purple cabbage juice

Chrysanthemum juice

Black wolfberry juice

Purple cabbage (or rose or black wolfberry)

Soapy water

Mr. Muscle cleaner

Yakult drink

Pure milk

Sprite drink

Grease cleaner

Green tea drink