Friday, April 5, 2013

Chemistry week before spring break

This week in chemistry, we did 2 labs. During one of the labs, we used lab tools to figure out the amount of copper in this substance. On Thursday, we made a fire by burning off the chemicals in a different substance. We then roasted marshmallows in the fire.

Saturday, January 19, 2013

Week 17

over the past few weeks, we have been exploring many new ideas and concepts in chemistry.
first we learned about chemical properties/changes.
Chemical: associated with identity change
Chemical properties: flammability, oxidation, toxicity, chemical stability, combustibility
The we learned about the difference between compounds, elements, and mixtures.
i learned that compound is 2 or more atoms of different elements bound together and that elements are atoms that share all properties together. (Physical properties and chemical properties
A Mixture is 2 or more pure substances that are mixed together without being joined
Also over the past week, we have been learning about the period table of elements. We learned the difference between metals and non metals. For example:
Metals:
Solid at room temperature
Higher density
Hardness
Luster
Conductive(energy/heat and electricity)
Malleable

Non-metals
Liquids/gases at room temp
Poor conductors
No luster
Brittle in solid state
Then, we learned about the law of definite proportions which applies to elements like those of h20 where the proportion of the volume is definite.
Lastly, we did an experiment where we distilled Pepsi to see how much of it was water. Although we didn't figure out the answer, we figured out how to evaporate the water out of the Pepsi so that we could measure the amount.



Sunday, November 18, 2012

Chemistry week 10

This week in chemistry, we focused on learning about energy and heat. 
On Monday we had to do an experiment to figure out which would change the temperature of 500 mL of ice water more, 10 mL of 50 degrees Celsius or 100 mL of 25 degrees Celsius. I predicted that the 10 mL would heat up the water more but I was wrong. The 100 mL changed the temperature of the water by 1.5 degrees Celsius and the 10 mL of water didn't even change the temperature. This is because there was more energy added to the system. To help understand this concept, we watched a video. It explained that if you had a teacup full of $100 bills and a bucket full of $50, the bucket would have more money in it, which represents the energy. So even though the bills themselves are worth less, as a whole they have more energy than the teacup.
On Tuesday, we learned that the degree of hotness only depends on the speed whereas the quantity of hotness depends on mass and speed. The degree of hotness is the temperature and the quantity of hotness is heat. In previous science classes, we have been taught that energy is like Baskin' Robin's 31 flavors basically and that there is many different "flavors"  of energy. Mr Abud made a statement to help us understand this which was that if you scooped vanilla ice cream out of the container, it wouldn't turn into chocolate when you put it onto the cone. There is just ONE flavor of energy. It is just energy. Energy is energy is energy. Energy can be stored and transferred in different ways. So really, all energy is the same, and just stored different.
On Wednesday, we learned more about energy. Energy maintains its identity after being transferred, it doesn't change into a different type. Energy can be stored and it is substance like, but isn't a substance that you can touch. It can flow or transfer from one system to another. The different ways that energy can be stored are the following:
1. Thermal Energy (Eth): Energy stored by moving particles.
2. Phase Energy (Eph): Energy stored in the system due to the arrangement of particles that exert attractions on one another.
3.  Chemical Energy (Ech): Energy due to attractions within molecules.
On Thursday, we did an experiment to figure out how the temperature changed in a system based on the energy we added to it. we put a glass of ice on a hot plate and kept the temperature at a medium hot so that it would transfer from a solid to a liquid to a gas. We only made it to about 95 degrees Celsius but the general trend of the graph of the relation was that as we increased the energy, the temperature increased.
On Friday, Mr Abud wasn't there so we worked on a worksheet. I learned about what a triple point was, which was that it is a point where all three stages are present basically. Like the point where there was a little bit of ice, a little bit of water, and water vapor all in the system like it was on Thursday. At the end of class, we had a lockdown and we almost all died, but not really. 


Tuesday, November 6, 2012

Chemistry Week 8

This week in chemistry we learned about different units of temperature and did things with glowsticks.
On Monday we learned about the measurment of temperature called "Kelvin." -273.15 degrees Celcius is called absolute zero and is equal to 0 Kelvin. It is known as the absolute scale.
To convert celcius to kelvin, you add 273.15. To convert Celcius to Farenheidt, you multiply celcius by 2 and add 32.
Then, we focused on pressure. We compared 2 different 2 L bottles that both had a dropper in them and saw that when the cap on the bottle was screwed on, it was harder to move the dropper down than when it was unscrewed.
On Wednesday it was halloween so we did stuff with glowsticks. We found out that when you put glowsticks in hotter water, they glow brighter then when you put them in cold water.
On Thursday, we learned about pressure in the atmosphere and Mr. Abud assigned us a project to make a barometer over the weekend. A barometer measure the atmospheric pressure. We learned that we are the spongebob's of the air.
On Friday, we went to the computer lab and we took a group assessment.
Overall, this week was not too eventful but we learned a lot of important information.

Sunday, October 28, 2012

Chemistry Week 7

This week in chemistry, we learned some knew formulas and came to a few consensuses.
First, we went back to discussing the experiment we did last week with the ethanol and the water. We figured out that ethanol requires less energy for its particles to expand because its less dense. 
After that, we came to a consensus that temperature is a measure of the energy of particles, measuring the speed of the particles (velocity). The average velocity (energy) of all of your particles is your temperature! 
On Tuesday, we focused on pressure. Pressure is equal to Force(newtons) divided by your Area (meters squared). We measure pressure in Pascals (Pa). According to this formula, if you decrease your area, your pressure increases and if you increase your force, the pressure will increase. Some factors that might affect the pressure of a gas would be the volume of the gas and the temperature. For example:
The pressure of the gas in A would be greater because the volume is less than in B.
On Wednesday, we used a pressure reader thingy and a syringe to find out what happens when you change the volume of the pressure source. We found out that as your volume increases, your pressure decreases. We also had to find the formula of what was going on. We used the inverse and found of that P(pressure)=k(constant)1/v(volume). The k or constant of proportionality equates 2 things. In this case, the constant was the TEMPERATURE. So, Pressure=Temperature/Volume 
On Thursday, we had to complete another lab to figure out if you keep the temperature and volume constant but change the number of particles in the volume, what would happen to the pressure. we figured out that if you increase the number of particles in the same amount of volume, your pressure increases. 
On Friday, Mr Abud wasn't in class so as a ChemTeam, we had to create a study guide for our quiz on Wednesday. 

Sunday, October 21, 2012

Chemistry Week 6

Chemistry this week focused a lot on just plain learning rather than doing labs.
On Monday and part of Tuesday, we went over our summary of unit 1. Doing this helped me just basically sum everything up and understand everything we learned as a whole. Once all the groups were done presenting their whiteboards, we did a sort of lab with popcorn and dry ice.
The dry ice was super duper cool and looked like it was floating on the table. We used this to show how this substance went from a solid straight to a gas. We drew a particle diagram about this. My groups looked like this:
We used the arrows to simulate the particles moving away from the solid part of the dry ice. Then, we did a lab with the popcorn. Everybody closed their eyes and Mr Abud opened up a bag of popcorn. We had to draw a particle diagram for how the smell travelend and it looked the same as the dry ice diagram we drew.
On Wednesday, we got new seats... Then we did a mini lab about with these two test tubes containing water in one and ethonol in another. We put them both in a container that had water in it and put it on a hot plate. As the water heated up, the amount of ethonol and water in each tube rose in the little thing on the top. We learned that this is how a thermometer worked. After that, we watched a video that Mr Abud took of dropping food coloring into a container of cold water and one of warm water. The red food coloring that was dropped into the warm water spread faster than the blue food coloring in the cold water.This was because the water molecules of the hot water were moving around more because the water was closer to the gaseous state since it was heated up. Then, we watched one of these weird Eureka videos about what was saw going on. Basically we learned that matter NEVER stops moving, in every state.
On Thursday, we discussed all of these things  and took some notes. We compared solids, liquids, and gases and learned some new terms. Fluidity is how much a liquid flows (applies to liquids and gases). Rigidity is the rigedness or stifness of a solid. Viscosity is the resistance to flow, like Mr Abud's hair. In a solid, the particles are moving, but not very musch. They have a consistent structure called a lattice structure. It is the most dense state and it is rigid. In a liquid, the particles are moving more than in a solid. It is less dense than thes olid and has more fluidity. It doesn't have a lattice structure, instead it takes the shape of the container. It is also warmer than solids. In gas, the particles move the most. It is the last dense stat and has the most fluidity. It has no structure and is the warmest state. 
Lastly, we learned the Dance of the Little Lumps (Molecules). We can demonstrate them using "wooshies" in the following ways:








 


Sunday, October 14, 2012

Week 5 Reflection

In chem this week, we basically focused on one thing. That thing was finding the density of a boy vs. a girl. On Monday and Tuesday, we planned out on how we were going to do this. 
At first, we thought that we should use the school pool to figure out the displacement of the water so that we could find the volume of the student so that that we could divide that into the mass. We realized that it would be too hard to figure out the displacement of a person in the pool because a human wouldn't really displace much water in a huge pool. Then we thought maybe we could use a dunk tank type of thing, but we didn't know where we could get one. We ended up figuring out that we could use a 44 gallon trash can. Thomas and Shannon volunteered to be the two students that we would find the density of. They told us their weight and we converted it into grams for the mass and then on Wednesday, we started the lab.
We put a kiddie pool underneath the trash can to catch the displaced water so we could measure it and then we filled up the trash can. Once it was filled to the top, Shannon got in and went all the way under and a bunch of water was displaced and spilled over the top. We then measured how much water fell into the kiddie pool. To do this, we filled up 2 L pop bottles so that it was easier to figure out, and then converted it into mL. Then to find out the density of Shannon, we divided her mass by her volume and it ended up as  .9951 g/mL. We did the same for Thomas and his was 1.047.
On Thursday, we talked about our results.These two densities were very similar and it was too broad of a generalization to say that boys have more density than girls. There were some factors that could have skewed our results, like the water that spilled out of the kiddie pool and the lack of accuracy used in measuring the amount of water. Also, the density of a human depends on their weight and volume, not on their gender. So if somebody, for example, is very fat but has less volume (shorter), they will have a greater density of somebody that is skinnier and has more volume (taller). None of this depends on your gender, just on the person in general.