Photo Journal

To view any setups discussed on this page, please refer to our Methods page.

Day 1- April 10, 2002- Today our project was to set up our material for the photo shoot.  We are using a still camera with a photo gate setup with funnels to navigate the lithium through.  We encountered problems because we had to find a way to insure that the lithium would pass through the photo gate's light beam to set off the flash.  Once we had a setup that looked like it was working we practiced with paper pieces about the size of the lithium and later switched to BB's.  The flash is now presenting problems because it is still not going off every time and we are still working on finding the correct delay time (which we calculated to be about .054 sec using d-v-a-t).

Day 2- April 11, 2002- After discussing our setup with the class we decided to try using a digital camera with a continuous light source.  We got the equipment and set it up as shown on our Methods page.  Instead of using the funnels we were able to drop the lithium into the water manually without a problem.  With the shutter at 1/2000 s we were able to capture all parts of the reaction.

Day 3- April 15, 2002- We used the video camera again today.  The only change made to the settings on the camera were to change the shutter from 1/2000 to 1/1000.  The setup was charged by placing the continuous light source behind the reaction for a backlit effect.  We did this by putting a carousel lamp behind two pieces of white Plexiglas.  This illuminated the subject but diffused the light enough that we were still able to see the reaction on film.  This setup is shown on our Methods page.

Day 4- April 16, 2002- We continued with the same setup, experimenting with different angles to watch the reaction at.

Day 5- April 17, 2002-  After reviewing the video from the previous days we decided to go back and try some new things.  We decided to try moving the camera to a new position above the reaction so we wouldn't have to worry about the edge of the beaker getting in the way of the shot.  We decided to keep using the larger beaker with water filled above the rim.  Our light was still backlit.  This setup is shown on our Methods page.

When we were watching the video we also noticed that there were gas fumes visible from the reaction. In order to take a closer look at this phenomena we devised a setup whereby we could observe the silhouettes of the plumes on a white reflective background.  For this setup the carousel was position in from of the reaction and the light beam was focused onto one spot of the background using a special slide in the carousel.  The settings on the camera remained the same throughout the day however it was necessary to manually focus on this part of the experiment.  This setup is shown on our Methods page.

Day 6- April 21, 2002-  Today we tried a setup that allowed us to tape what was going on from the bottom of the container.  We propped up the camera with foam inside a small aquarium.  We put the water container on top of the aquarium and used a light from overhead. We used hexane to clear the excess mineral oil from the lithium.  We put phenolphthalein in the water to see where the lithium reacted with the water. (This didn't work as well as we'd hoped.  It didn't make a distinct trail; it was too smudgy and it quickly turned all of the water pink..) 

Day 7- April 24, 2002- We began by using the same setup today as it was on Day 6.  We hoped to focus more on lithium from underneath to get a clearer picture of the bubbles.  This time, we did not use phenolphthalein.  This setup is shown on our Methods page.

Then, we used the same setup to film sodium.  We found that the sodium forms a ball quickly after hitting the water.  We were afraid that the clouding of the water would prevent us from seeing up through the container, so we made a new setup.

In the new setup we placed the camera on a tripod next to the container.  We used the same lighting.  We didn't rinse the sodium in hexane because we thought that it was perhaps the reason that the water got so cloudy.  

Day 8- April 28, 2002-  After reviewing the footage from our previous photo shoot we were intrigued by the propulsion of the sodium throughout the water.  We observed the direction that the sodium took after the initial drop and made several hypothesis on what could determine the motion.  To analyze this further we decided to do several more experiments with sodium.  Using the same setup with a bottom view we did three more experiments using sodium.

After that we decided to move on to potassium.  We had been warned prior to the drop that we would need some sort of a shield as well as safety goggles to shield from any metal sparks which may come off during the reaction.  We decided to stay with a bottom view for this reaction since it was already setup.  After we found a piece of clear Plexiglas which would not distort the light we dropped our first piece of potassium.  This reaction was very hard to see and very short-lived.  We decided that a possible cause for this was the cover on the beaker was not allowing enough air in to keep the reaction going and also making it very difficult to see because it was not allowing the fumes to escape.  We remedied this problem in the next drop by drilling a hole (approximately 1cm across) into the Plexiglas shield.  This allowed the reaction to last longer but we still encountered problems with vision obstruction.  We tried lowering the water level next which gave the reaction more air to react and also provided a greater amount of space for the fumes to clear so more of the reaction was visible.  This setup is shown on our Methods page.

Day 9- April 29, 2002- Before we began today we increased the size of the hole in the Plexiglas shield.  

We did this to allow more of the fumes to clear away from the reaction.

Once this was done we began by dropping potassium and videoing from a bottom view.  We did three more potassium reactions from this angle so we could compare our best data to draw conclusions later.

Next we switched to a side view of the reaction.  For this setup we used the same setup from Day 2.  This setup did not silhouette the reaction so the visible portions were very sharp.  Initially we had problems with the focus which we solved by moving the camera further away and zooming in.  We then used manual focus.  We used a side view of the camera for  three potassium reactions and two sodium reactions.  We did not do lithium from this angle because we had so many video clips from this angle before.

Next, we decided to do top views of all the reactions.  Our setup for this was to have the camera and tripod on top of the camera with the beaker positioned underneath.  The light was kept in front.  This setup is shown on our Methods page.

We started with sodium and got very nice footage from that the first time.  When we tried to zoom in further on the next two reactions we were not able to see what occurred when the sodium moved off screen, so in that respect it was not as good.

Then we dropped lithium.  We could not see that much from the first one because after it was dropped the reaction moved to the side of the beaker where it did not move.  The next drop was better but this reaction also moved on and off screen.

The potassium proved the most difficult to film.  Because it fogs the glass up so quickly only the very beginning of the reaction is visible with this view.  The second reaction filmed was the best we were able to do.  This footage shows the explosion of the metal.  Although it is not very clear until the metal hits the Plexiglas that an explosion has taken place.

Day 10- April 30, 2002- After reviewing the video clips of the potassium reaction with a top view it was obvious that having only two holes in the Plexiglas shield to let the fumes escape was not sufficient enough.  We decided to try to put the beaker inside the aquarium and place a Plexiglas lid over that to see if the reaction could be viewed better.  We only had time to set the equipment up but did not film.  This setup is shown on our Methods page.