K - 2nd Session 5: Using solid and liquid chemicals to launch rockets!

This week our budding chemists got to build their own rockets and were able to launch a few up in the sky!

Be began by refreshing the mind on the differences between a solid and a liquid.  We used water as the example of a liquid and a piece of cardboard as the example of a solid.  How do we know that water is a liquid?  How do we know that cardboard is a solid?  Once we were reminded of these differences we discussed the solid and the liquid that were going to be used to create a reaction.  The word reaction was studied and discussed as well, what does it mean?  For our young scientists the word reaction was defined as when something mixes with something else and causes something to happen : ) .  The liquid used was white vinegar, the solid used as baking soda.  Together, when mixed the "reaction" is what would shoot the rockets up!

The kids then constructed their rockets, once finished we went outside to do some trials and see if they could be launched.  Due to the 'explosive' nature of the reaction everyone was required to wear goggles and the young chemists did not handle the chemicals directly.

The lessons learned?

• We learned what a reaction is.
• We learned that a reaction using baking soda (solid) and vinegar (liquid) happens VERY quickly!
• We learned that the weight (how 'heavy') the rocket is determines if it will launch or not, so we either need to add more parts to the reaction chemicals or make the rocket smaller.
• Finally, we learned that in real life, in order for NASA to launch a space shuttle out into space it takes an incredible amount of rocket 'power'!  (To further study this concept with your young chemist visit http://www.nasa.gov/audience/foreducators/rocketry/home/what-is-a-rocket-58.html#.U3UDmvldWTk)

3rd - 5th Session 4: Soccer Science

We finally had a sunny, beautiful day to conduct part of our experiment outside!  Yay!  Or course our scientists were over the moon.  To start things out, we discussed some of the forces that play a key role in soccer: the force of gravity which is constantly pulling the ball downwards towards the Earth, and the force of air resistance which is the force of air pushing against a moving object.  We also talked about how having the best kick possible requires human force and energy and depends on the human component "time of reaction" which is how long it takes a human to develop a response to a stimuli.  Before getting outside and collecting data on velocity of the soccer ball after kick we gathered some data inside that could be crucial to the experiment: the mass of the ball, the circumference of the ball (because we also discussed how the direction of the ball is determined by where the foot hits the ball during the kick) and time of reaction (the human component).

Once we gathered this important data we headed outside to figure out the ball's velocity and how the velocity may change due to the forces discussed and the time of reaction factor.  A meter stick was used to measure the distance of how far the ball was kicked.  Velocity was then calculated using the formula: v = d , 

                                                                                                                                                 t

in which v stands for velocity, d is distance in meters, and t is time.

Once all data was gathered we went back inside and analyzed the velocities recorded, indeed the human component of time of reaction plays a key role to become the best athlete possible.  And then of course the question then becomes, can time of reaction be improved?  Another science quest for the young scientists!

K - 2nd Grade Session 4: Density!

In this week's session our young chemists learned about how fascinating density can be!  We first reviewed what molecules are (2nd session) and how molecules of different things look different and behave differently. We then talked about three particular types of molecules: water, alcohol, and oil.  The little chemists recalled how alcohol was 'lighter' than water from a previous session and we talked about how things 'mix' and what that means.  I introduced the word "DENSITY" and we talked about how the size of the molecules is important when mixing things - Which molecules are the smallest?  Can certain types of molecules 'get by' or 'push through' other types of molecules?  Density was defined as how 'big' something is and how much space it takes up in the world - like how water can take up some or most space in a container. We then made predictions about what would happen if we mixed all of the three types of molecules: water, alcohol, and oil.
To be able to identify the three different types of molecules we used food coloring: yellow for water, red for alcohol, and green for oil.  Then it was time to begin testing our ideas and see if our predictions were correct!

Right from the get-go the chemists made some discoveries and observations about the liquids - What type of smells were coming from the containers?  What what going on with the green food coloring in the oil?  Why did it look like bubbles?

Once all three liquids were mixed, the little chemists continued to make observations - they noticed how the green 'bubbles' in the oil were moving downward towards the yellow water and was mixing with it!  They noticed that the red alcohol was "going through" the oil, which molecules were 'bigger and took more space? What were these molecules showing us about density?

To conclude our session I added a new component to our experiment - we mixed two solids into the mixed liquids to see how these solids would react with the liquids and their densities.  We added some baking soda powder along with a tablet of alka seltzer!  Our young chemists predicted once again what would happen and the majority predicted an explosion so we all had put our goggles on for safety.  Below is a pic of what the chemists observed.

 Yes, all of the chemists held their tops down as they saw the red and green colors mix and rise to the top.  Thankfully there were no explosions but the chemists did observe how bottle expanded at the bottom/base and how the plastic tightened.  Yes, something fishy happened with density - the entire bottle showed that all these molecules mixed together created something 'bigger' which was took more than the space allotted by the original bottle.  Hopefully none of the chemists bottles exploded on the way home. (I apologize if they did!) - DENSITY!

3rd-5th Grade Session 3: Table Tennis Science!

This week we took a deeper look at the variables that make for a perfect serve and return hit in the game of table tennis.  To start out we first discussed those variables that are hard to control and those variables that we can control.  We defined those variables we can control as the independent factors in the experiment. Then each group came up with a working definition of what a perfect serve is so that we could have a point of reference when observing and analyzing the hit.  Once everyone defined "the perfect hit", we decided to test how the mass of the ball, an independent variable, affects the perfect hit.  To test this idea we used three types of balls: 1) a plush small basketball, 2) a plush baseball, and 3) a ping-pong ball.  Each group measured the mass of the balls using a scale as well as an electronic scale.  Before measuring the masses, we we went over how the triple scale is used.

After weighing the balls it was time to test out the idea!  After getting familiar with how the game is played, the trials began.  For each ball, students conducted four trials - two underhand hits and two overhead hits and recorded their results on a data table.  When  all the data was collected, the young scientists analyzed their data and looked for patterns and concluded that the heavier the ball is the harder it is to have a perfect hit.  We also discussed how in any sport where human power is involved the key to a "great" athlete is also learning how to control those muscles that make for a great "play" and thus is all about practice, practice, practice!

K-2nd Grade Session 3: Skittle Chromatography!

This week our young chemists used chromatography to study the colors that are used to make Skittles flavorful shells.  We first talked about what chromatography is and how chemists use it to learn about the make up of chemicals and answer questions about our world. Then we made predictions about what skittle colors would become visible after conducting the experiment.  We then got busy with the experiment!  As the liquid began to be absorbed by the filter paper we talked about how this "absorbing" is called capillary action and how it is exactly the same process that happens in our bodies as the blood from our legs "moves" up back to the heart (just a tidbit of biochemistry). All in all, our young chemists were able to connect how chemistry is related to our everyday life - even candy-making takes some chemistry action!

3rd - 5th Grade Session 2: Field Goal! The Science Behind a Perfect Football Kick

In this session our scientists studied the science of projectile motion and it's applications to kicking a football. First we discussed how projectile motion is involved in throwing, kicking, and punting a football and how professional players such as quarterbacks and kickers need to have a good understanding of how a football moves through the air in order to help them win games.  We then talked about what factors affect a kick such as distance from goalposts, wind, and amount of force/energy used when kicking the football.

We focused on distance in particular for this experiment.  The question that was raised was: How does changing the distance from the goalposts affect the accuracy of a field goal kick?  After reviewing what a hypothesis is (an educated guess) students discussed what their hypothesis was for this experiment.  Some students thought that increasing the distance would not matter, being that the main factor could be weather conditions.  Other students thought by decreasing the distance then the kicker would have a better chance of scoring a field goal.  In this particular experiment, a constructed sling shot represented the kicker, a meter stick was used to represent the football field (students measured distances in centimeters instead of inches), and two rulers attached to two cups represented the goalposts.

The first part of the experiment was to build the sling shot.  Students had to work together in pairs to construct a sling shot with the given materials and tools.  This part of the experiment required some engineering!

After the sling shots were constructed, the students set up the rest of the experiment and began to test their hypothesis by shooting a ball using the sling shot from different distances and recording their observations on a data table.  As a safety precaution all scientists wore goggles.

After testing out their hypotheses, students got busy analyzing their data by computing the field goal percentages for each "kick" from the different distances.  The percentages were calculated by using the following formula: (Math to the rescue!)

Field Goal Percentage = Number of successful field goals x 100

                                      Number of field goal attempts

With their partners, our young scientists made some conclusions based on their analysis.  In most cases, students observed that the less distance between the "kick" and the goalposts the more likely a "field goal" was made.  In some cases, students observed that the way the sling shot was constructed made a huge difference in terms of the force/energy used for the "kick" thus affecting the accuracy of the kick.

I then asked the scientists to think about something that they would change if they were going to do this experiment again. Some suggested we would get more accurate results if the wind factor was involved. Others thought their sling shots could have more improvements in their design.

We closed with going back to how professional football kickers and punters use math and science to achieve the best kick and how the human factor (being human) makes a difference in terms of achieving a successful kick.