Hobbies And Interests
Anodes and Cathodes
It is very easy to mistakenly mislabel anodes and cathodes. In fact, it becomes easier to do the more you know about electronics. There are devices like diodes and batteries which when observed closely seem to defy conventional logic. The simplest thing to keep in mind when it comes to separating the two concepts is to ignore their construction and look at what happens with current. In electrical systems, an anode is what receives current and a cathode produces it. This means that from a functional standpoint, a cathode produces a stream of electrons (called anions, or negative ions) which are collected at the anode.
Fluorescent Bulb Experiments
Fluorescent bulbs are designed so that the cathode within the bulb sprays electrons towards the anode separated by an electrically conductive gas. When exposed to alternating current, the cathode swaps places up to 60 times per second, producing what our eyes perceive as a steady glow. Many experiments are possible using these bulbs. You can create a frequency altering circuit and observe how light production is affected at various rates. You can expose a bulb to the electromagnetic field of high power lines or other devices to study induced current. Or you can study the light frequency emissions of various fluorescent bulbs under different conditions using a spectrascope.
Electrolytic Experiments
Electrically conductive metallic objects placed into aqueous solutions tend to break down. For this reason, manufacturers construct common metal items exposed to water (such as radiator parts) to minimize the electrolytic effect. This effect gives rise to interesting experiments. In one experiment, you can use iron nails half-coated in other metals such as zinc or copper and placed into an agar gel containing 3 percent sodium chloride, 5 percent potassium ferricyanide and 1 percent phenolphthalein solutions to observe which metal takes on the role of anode or cathode. In another project, you can also attach two different metals to the ends of a battery terminal in the same agar from before to observe how electricity promotes the corrosion-inducing reaction.
Electrolysis Experiments
You might be aware that water is composed of both hydrogen and oxygen, but not everyone knows that you can use electricity to break its bonds and separate it into its constituents. Oxygen gathers onto the anode and hydrogen on the cathode of an electrolysis apparatus. This capability creates several possible experiments. You can do experiments using electrolysis to determine which chemical compounds added to water promote speedier hydrogen gas production. You can also perform experiments where you break down high concentration solutions of sodium bromide or sodium chloride using the same process. The latter electrolysis labs should be performed in a well-ventilated area because of the potentially toxic gases produced.