What is the coolest experiment you've tried/completed?

For me it's just the most dangrous things, (yes, I am an adrenaline junkie ) such as P4 and Br2.
for A beginner I suggest reading woelen's site:
http://woelen.homescience.net/science/chem/exps/index.html
for a beginner the best things are experiments that involve color change, chemical chamelion,...

I electrolyzed a gram of sodium metal right into a sealed light bulb.

I picked out an incandescent bulb that was under a vacuum (one where the filament is a long,
straight or single spiral tungsten wire; and not a double-spiral) like this:


The filament when energized became a thermionic emitter, and as such was the cathode. For
best results the end of the filament closest to the tip of the bulb was chosen for the (-) connection.
The higher the wattage of the bulb the better, as the filament is carrying not only heater current,
but cathode current as well. A sacrificial graphite rod was the anode, and the bath was
barely-molten pure NaNO3. Connections were soldered to the base of the light bulb, and it
was suspended upside-down in the molten bath. With 200V DC from cathode to anode, it wasn't
long before a silvery mirror began to form in the top part of the tube. After several hours quite
a bit of sodium had formed around the base of the bulb, and cool air was passed constantly
across its surface in an attempt to keep the metal solidified.

After several hours the vapor pressure of the sodium crept upward, until "BINK!" The
current shot upward, the pure yellow glow of the sodium flare lit up the room.

The sodium began to melt in the tube, and suddenly a blob of it ran down to the tip of the bulb.
When this happened the bulb abruptly cracked, sucking in molten NaNO3. A lot of the
product was thus lost, but not completely since the salt solidified in the bulb quickly,
and its decomposition with sodium filled the tube with nitrogen gas, creating positive pressure
in the bulb.

Here is a picture of one that I did on a smaller scale, using a 7W "night light" bulb:


The sodium in there will stay bright and shiny as long as the vacuum in the bulb lasts.

I noticed that the stem inside the bulb turned black. This is probably silicon that was reduced
out of the glass by the sodium vapors. This part of the bulb would be quite hot, due to its thermally
isolated position. The outer envelope of the bulb was faintly darkened after the experiment.

[Edited on 14-11-2013 by WGTR]

Quote: Originally posted by CO2AtmosphereGuy

I'm trying to overcome my chemophobia and learn about chemistry, but there doesn't seem to be many exciting experiments for the novice. What keeps you interested in your home lab? What excites you about chemistry? What's the coolest thing you've done? Your answer doesn't have to be a beginner's level experiment.

I loved doing chemoluminescence experiments, such as making and oxidizing Luminol with and the bisphenyloxyoxalates with H2O2 and other oxidants. I also liked making rocket engines and other pyrotechnics, although I did quickly learn that they are best done outside wen you are starting to protect the house from fire, smoke, spills, and screaming parents. Colored fire, smoke, spontaneous combustion and other tricks are fun.

I even volunteered to make a "volcano" for a science class. The teacher thought I was being meladramatic when I said it had to be "erupted" outside, but once she saw it erupt, I think she was surprized by how much fire can come out of a students volcano model. I covered most of the school in smoke (from the outside, fortunately), having more than a pound of various pyro compositions in my tin can built into the top of the volcano. Now, I would be arrested for building a weapon of mass destruction...

I also remember freezing mercury onto a stick with LN2 in middle school to make a hammer which could drive nails. One of my friends built a dye laser in high school, that was pretty cool. But for some reason it did not attract girls as well as I would have thought.

A good source of relatively easy and interesting experiments, that will teach you the basics of experimenting is to get your hands on an undergraduate lab manual, as a lot of the experiments described within are quite simple and will teach some basic chemical principle e.g coordination chemistry

Quote: Originally posted by CO2AtmosphereGuy

What is the coolest experiment you've tried/completed?

i dont think that experiment has come to its completion yet

INSUFFICIENT DATA FOR MEANINGFUL ANSWER.