Fair Test: I will make sure to make my experiment as fair as possible; therefore I would get the reliable results. To make this experiment fair, I will do the following things.
1, I will same experimental equipments as the other group does.
2, I will measure (weight) the chemicals and water carefully to prevent any inaccurate results.
3, I will count the time carefully and do exactly what teacher told me to count to prevent any anomalous results.
Prediction: I predict that the proportion between water and the germination of seeds will be directly, and the proportion between sodium metabisulphite will be inversely. I predict that the amount of sodium metabisulphite will be inversely proportional to the number of seeds germinated because of couple of reasons. Firstly, sulphur dioxides are harmful chemicals, and sodium metabisulphite is one of them. Secondly, it is one of the main reasons to cause the acid rain, the acid rain contains water and some sodium dioxides, when it rained on the ground, and the sodium dioxides reacted and damage all the seeds. Those were the reasons for my prediction.
Method: For the first experiment, I need the following apparatus - some pots, a sealed bag, an indicator, cress seeds, some cotton wools and sodium metabisulphite. Then, I will put some sodium metabisulphite into my first pot and let it cover the bottom, and I will put about 10 drops of water in and seals the bag. Secondly, I will put 6 drops of indicator into it and seals the bag, and wait for about 5 minutes. Thirdly, I will put some moist cotton wools and place 20 seeds all over the pot randomly, then put the pot in a moisture place and leave it for few days.
After few days, the indicator’s colour changed to red from blue, which means the sodium metabisulphite reacted with air and affected the indicator. And all the cress seeds have all germinated.
For the next part of my experiment, I am doing to investigate how does sodium metabisulphite and water (Solution A) affect cress seeds.
This time, I need some pots, 2 bags, cotton wools, 40 cress seeds and some solution A. Then, I will put the sodium metabisulphite and water into the first pot as same as the last one. And I put some moist cotton wools into the other two pots, and put 20 seeds into each pot. Then I put the first pot (Solution A) and the second pot (Cress Seeds) in a bag and seal it. And put the last pot into another bag. Leave it for few days.
After few days, I have got the results. The table that was shown below are the results of whole class (9 Groups), the forth was my group’s result.
The bar chart above was shown the table directly.
This time, I am going to investigate how does different concentration of solution A affect the germination o cress seeds. I have chosen 6 different concentration of solution A to do this experiment, which are 30:0, 28:2, 26:4, 24:6, 22:8, 20:10 with 30cm3 water.
For this par, I need pots, 6 sealed bags, cotton wools, cress seeds and some solution A. Firstly, I will fill the first pot with water and second pot with sodium metabisulphite. Secondly, I put cotton wools in to next 6 pos and let them cover the bottom, and I put 20 seeds into each pot. Thirdly, I measure 30cm3 water and pour it into the first pot, and I will place it into the bag. Then, I just repeat the last step to the other pots with different concentration of solution A. and leave it foe another few days.
After few days, I have got the results. The table below shows the results.
Obtaining and Analysing:
The graph below shows that the number of seeds germinated against the amount of water involved.
