Today we went to the science lab and got started with our rusting experiment. Theo was absent, so I was unable to complete our experiment. Our experiment was to have three screws. One normal one and one covered in cloth tape.
Here are my predictions:
|Cloth tape covered screw in salt water.
||I predict that the screw will rust slightly due to the little liquid particles inside the gaps of the tape that aren’t visible.
|Normal screw in salt water
||I predict that the screw will rust because it doesn’t have any protective layer of any sort.
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Science Experiment: Rusting (Part 1)
- Why don’t some metals rust?
Because some metals have a protective covering on their suffuses such as aluminium is protective by a layer of aluminium oxide preventing a reaction between oxygen and metals.
2. Why does it take some things longer to rust then others?
Because some metals have stronger and more protective layers than others
3. Why do materials rust?
Materials rust because of the compound because of the reaction between metal and oxygen.
4. What does rust look like?
5. How can rust be prevented?
Rust can be prevented before hand by avoiding an oxygen hit metal or by continually oiling it. It is irreversible.
6. Why does iron rust in water?
When water hits iron, it mixes with carbon dioxide in the air. This mix creates a weak carbonic acid, an electrolyte that starts to dissolve the iron. The dissolved iron then combines with the oxygen freed from the water.
7. Is the brownish things that grows on plants rust?
No. It is fungi.
8. Is fungi a form of rust?
Aim: To prevent rusting temporarily by covering 2 bolts with cloth tape and scotch tape.
Materials: Cloth tape, scotch tape, 2 bolts
- Arrange items necessary for the experiment (cloth tape, scotch tape, 2 bolts).
- Cover the first bolt with cloth tape so that no gaps are visible.
- Cover the second bolt with scotch tape so that no gaps are visible.
- Come back a day later and unravel the tape off each bolt.
- Observe what happened and the differences between the two bolts.
Hypothesis: I predict that both bolts will rust slowly due to the little oxygen particles inside both tapes.
On June the 12th, 2014, Chris and Maria came to our school for our final lesson. We learnt about fair test and rusting. We learnt about independent variables, dependent variables, controlled variables and control. We did a couple of experiments to explore this more.
Some things I remember are that an independent variable is the condition that is changed by the scientist. I remember that a dependent variable is what you measure in response to the independent variable. A controlled variable is a condition that is kept the same throughout the experiment. I remember control is a similar test where the independent variable is left unchanged to produce a comparison.
Some things I know understand is that different temperatures change the results by a vast amount. For an experiment to have the same result. Nothing must me changed. The same amount of heat should also be considered.
A question I am still left with is why does an alka-seltzer tablet dissolve faster in hot water than cold water?
On the fourth of May, 2014, Chris and Jacinta came to our school for our fourth lesson. We explored the concept of chemical change to broaden our knowledge on irreversible and reversible change for our mini project.
We started off by applying our prior knowledge. We had to find some objects that were reversible and irreversible. After that, we started five experiments. We had to predict, observe and explain each one. Then we had to decide whether each one was reversible, or irreversible.
Some things I remember are that a reversible change is a change that can be overdone and that you can get the original substance back. I remember that a reversible change is often called a physical or temporary change. I also remember that an irreversible change is permanent and can’t be overdone.
Some things I know understand are the reactions of a chemical change. I understand how dangerous different chemicals are and understand that just a simple little change such as adding one oxygen can make a completely different and extremely dangerous substance.
I have learnt a lot during this lesson, but I am still unsure about some of the reasons why chemical changes happen.
Topic: Submerging Packing Pellets
Aim: To observe a packing pellet’s reaction when submerged in room temperature water.
Materials: 1 beaker, 60-80 ml of room temperature water, 1 packing pellet.
Procedure: Fill your beaker with at least 60 ml of water.
Then gently place the packing pellet into the water.
Hypothesis: I hypothesize that the packing pellet will gradually sink and become soggy due to it’s reaction to water. The air in the packing pellet will be released.
Results: The packing pellet is expanding. It is slowly sinking as it absorbs water. It is getting soggy and has gradually stopped sinking. It is starting to dissolve.
Conclusion: Once the polystyrene element hits the water, the air inside it is slowly let out. Soon, the packing pellets started to absorb the water causing it to expand. Afterwards, the particles started to dissolve due to the change of state (solid-liquid).