* 1. Please identify the school where you performed the Magnetic Fluids experiment:

* 2. In what grade are you currently enrolled?

* 3. After performing this hands-on activity, please rate how well you understand the following concepts:

  Not at all A little Mostly Very
When the sizes of magnetic particles are sufficiently small (approx. 10nm, i.e. nanoparticles), they become single tiny magnets, align to the vector direction of a magnetic field, and are affected by the force from the magnetic field, hence forming a magnetic fluid in a solution.
To create one unit of magnetic nanoparticle (Fe2O3), we must provide the exact stoichiometric ratio of two units of FeCl3 and one unit of FeCl2. Incorrect concentrations in our redox reaction will produce other type of nanoparticles that do not have the desirable magnetic properties.
Solid materials can be dispersed in the colloidal suspension if their sizes are very small, on the order of ten nanometers.
Please offer your explanation to the following questions:

* 4. What happens to the magnetic nanoparticles in the solution if their size become too big (larger than 100 nm)? Explain your answer:

* 5. The solutions you have in the beginning of the activity were FeCl2, FeCl3, and ammonia. From where did the magnetic nanoparticles (Fe2O3) come from? Identifying or naming the chemical reaction is acceptable.

* 6. What is the role of that 1 ml drop of Tetramethyl Ammonium Hydroxide (TMAOH) in this experiment?

* 7. In this experiment, a droplet of NH3 is used to start the nucleation process around where the Fe2O3 atoms form and grow into a nanoparticle of approx. 10 nm size. Raining, or forming water droplets from gaseous water molecules (humidity), also involves a nucleation process. Please suggest what in the atmosphere might be equivalent to NH3, a nucleation center around which water droplets form and initiate rainfall.

* 8. Identify any concepts that you might have better understood after performing this activity:

* 9. On a scale from 1 to 4, where 1 means "not at all" and 4 means "very much," rate the following

  1 2 3 4
Did you find the science you learned in this activity interesting?
Do you want to learn more about how to modify material properties?
How well can you explain what a magnetic fluid is to someone who doesn’t know (perhaps a younger sibling)?

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