Name _Emily Sangder_________________________________________________
Date__2/11/13________ Period__1____
Forming the Investigation
Manipulated Variable (I change)
independent: type of environment
(saline solution, tap water)
Response Variable (I measure)
dependent: Amount of rust on
steel/iron nail
1. What is the question I will answer with this investigation?
Which environment, saline solution or water, would make the steel/iron nail rust more?
2. Background Information: Several things I already know about this topic, that will
help me to design a successful investigation, are
1)
2)
3)
4)
I know that steel with no coating on it will rust within 3-5 days
Iron will rust in water
Most metals will not corrode/rust in only air
Iron, Magnesium, Copper, and Zinc will all corrode in some type of enviornment
3. Predict in words what I think will happen during my investigation (hypothesis).
Then, use the graph to sketch my predicted results.
I predict that the steel/iron nail will rust more in the saline
(salt water) solution than in the regular tap water.
1
Name _Emily Sangder_________________________________________________
Date__2/11/13________ Period__1____
Designing the Investigation
Variables I will keep the same for a fair test:
Rating Scale
= 0 to 5
Amount of liquid
= 10ml
Type of Nail
= uncoated
steel/iron
number of days
= 5 days
enviornment
= saline & water
Safety: no use for goggles because there are no harmful substances being used; do not
touch or move anybody else’s experiment
Materials: 2 petri dishes; saline solution; paper towels; tap water; 3 steel/iron nails
Numbered and detailed procedures with a drawing of my set-up.
1)
2)
3)
4)
5)
6)
Place 3 layers of paper towel into a petri dish
Add 1 steel/iron nail to the petri dish
Pour 10ml of water into the petri dish
Place the lid on top of the petri dish and set petri dish aside
Take another petri dish and place 3 layers of paper towel inside
Take another steel/iron nail and place on top of the paper towel inside the petri
dish
7) Pour 10ml of saline solution into the petri dish
8) Place lid on top of petri dish
9) Label petri dishes with a sticky note of which liquid is inside
10) Let both dishes sit for 5 days
11) After 5 days, use a rating scale of 0 to 5 of how much rust is on the nail and on
the paper towel (5 being the greatest amount of rust, 0 being the lowest)
12) Compare the ratings of the 2 different environments to come to your conclusion
of which environment causes the nail to rust more
2
Name _Emily Sangder_________________________________________________
Date__2/11/13________ Period__1____
Collecting and Presenting Data
Title: (Top) Rating of Amount of Rust on Nail; (Bottom) Rating of
Amount of Rust on Paper Towel
Type of Nail
Enviornment
Rating of Rust on
Nail
Steel/Iron
Saline
4
Steel/Iron
Water
5
Type of Nail
Enviornment
Steel/Iron
Steel/Iron
Saline
Water
Rating of Rust on
Paper Towel
5
2
Title: (Top) Rating of Amount of Rust on Nail; (Bottom)
Rating of Amount of Rust on Paper Towel
5
4
3
2
1
0
-------------
covered or almost covered in rust
2/3 covered or more in rust
about half-covered in rust
has some rust, not a lot
barely any rust, but still visible
no visible rust on nail
3
Name _Emily Sangder_________________________________________________
Date__2/11/13________ Period__1____
5
4
3
2
1
0
-------------
a lot of rust surrounding nail
quite a bit of rust around nail
some rust around the nail
a little bit of rust around the nail
barely any rust around the nail; still visible
no visible rust around the nail
Analyzing and Interpreting Results
Question: (from p. 1)
Which environment, saline or tap water, would make the steel/iron nail rust more?
Introductory Sentence: In this investigation, I measured the amount of rust on 2 uncoated steel/iron nails after they had been sitting in 2 different environments for 5 days. 4
Name _Emily Sangder_________________________________________________
Date__2/11/13________ Period__1____
1. Evidence
2. Explanation:
In our investigation of measuring the
The reason we got the results we did
amount of rust on 2 steel/iron nails in
was because the nail sitting in the water reacted with the water, so it corroded. The nail different enviornments
in the saline also reacted, but not as much as the we found that after 5 days of letting the nails nail in the water so it didn’t corrode as much as I sit in the 2 different environments, both nails could see on the nail because there wasn’t as rusted, but one more than the other. much rust on the nail sitting in the saline. For example on my graph and data table, you can see that the nail that was sitting in water got a 5 on the scale, while the nail that was in saline got a 3. So the nail that was in water rusted more. Problems
There were the following problems during
the investigation: When I got my data on the 5th day, I saw that the nail sitting in the saline had a lot of rust on the paper towel, but not as much on the nail. It was the opposite for the nail sitting in the water. That one had a lot of rust on the nail (covering the whole thing) but not as much on the paper towel. I wasn’t sure what to make of this data, so I created another data table just for the amount of rust on the paper towel. 3. Conclusion
In conclusion, our results show that the uncoated nail rusted more in the tap water, but the paper towel had more rust on it in the saline environment. A future experiment or revision we could
do is to compare different types of nails, and use a rating scale to determine which nail would rust more in a saline (salt water) environment. This would have caused our data to be
confusing because without the extra data table, I would not have been sure how to rate the amount of rust. 5