Blog Week 25

On Monday, we turned in our electroscopes. We tested them by rubbing a balloon to our shirts, then I put the charged balloon to the copper coil on the top of the jar. I know it worked because once I put the balloon to the copper coil the aluminum foil leaves that were in my jar, connected by the copper coil, moved apart. The way this all worked was: when I rubbed the balloon to my sweater it collected electrons, then when it was put to the copper coil the copper took the electrons from the balloons, then those electrons charged both aluminum foil leaves with negative charges, which caused them to repel against each other. Once the aluminum foil leaves and electroscope were charged, I put a zinc plate to the copper coil at the top of the jar and doing that took away the electrons in the aluminum foil leaves, and once the electrons were transferred to the zinc plate, the aluminum foil leaves didn't have a charge so they didn't repel. Here are some pictures below:

  

On Tuesday and Wednesday, I was absent. On Thursday, we mixed calcium acetate, which an ionic compound and ethanol, to make sterno. Once we mixed the two things together and they combined making a solid, we light the solid on fire and it made a fire. Then we roasted marshmallows. Here are some pictures of our fire:

  

On Friday, we don't have school. Hope you have a great spring break!

Blog Week 24

On Monday talked about an experiment, we did a stimulation on the internet of rubbing a balloon on a sweater and seeing if it attracts to the wall and sweater. When the balloon was rubbed against the sweater, the balloon took the negative charges through static friction. The balloon got a negative charge and the sweater is now a positive charge and the wall has a neutral charge. The balloon was attracted to the sweater because they had opposite charges. The balloon was also attracted to the wall, but it was a very small attraction, because the wall had a neutral charge. This picture below shows the balloon attraction to the sweater and the wall.

We then learned some terms. Neutral has equal (+) and (-), evenly distributed charge. Charged is unequal (+) and (-) charge. Polar is equal (+) and (-), but uneven distribution. Dipole are organized charges at different ends, they are exact opposites. We also learned that the only charges that move are negative charges. Tomorrow we are learning about how charges have to do with compounds. On Tuesday, we talked about dipoles. We found out that H2O are dipole atoms. Which means that oxygen has a slightly negative charge and hydrogen has a slightly positive charge. So when two H2O atoms are by each other the oxygen attracts to the hydrogen molecules. The structure that it makes is called a crystal lattice structure. Water melting means enough energy to separate the attraction of each molecule between each other. IMFs are intermolecular forces, electrostatic attraction between molecules because of dipoles. IMF is also a dipole interaction involving H atoms in molecules. We then learned that ions are atoms with a charge and an atom that has an unequal amount of (+) and (-) charge and lastly it loses or gains an electron. If Na atom loses an electron then it turns in an ion and becomes a Na+1. If Cl atom gained an electron then it turns into an ion and becomes a Cl-1. We found out that electron carriers are oxygen and NAD+, they transfer electrons to other molecules. To make ionic compounds it would be like this: Na+1<-->Cl-1 = NaCl. On Wednesday, we did a worksheet. I understood question 1-4, but the rest were very difficult. I tweeted out my answers and these pictures show my answers to the questions.

On Thursday, we were to do the worksheets skill practice 19 and chem Quest 19. I worked alone on both worksheets. I understood the answers once I worked backwards on how to find the answer. I hope I have the right idea. I was going to redo the worksheets to practice for the assessment tomorrow. I hope I can understand it enough to do well on the assessment. Also, I tweeted my answers to both worksheets. On Friday, we took an assessment. I felt like I did pretty good, I understood almost all of it. I hope I did good.

Blog Week 23

On Monday, I was absent. On Tuesday, I was absent. On Wednesday, we talked about the lab that was done on Tuesday. I didn't really follow the talk about the lab. I learned that an electron is smaller than an atom and it has a negative charge. Atoms where discovered by John Dalton, while electrons where discovered by JJ Thomson, he did the experiment that proved electrons had a negative charge. In the atom there's a positive charge all around the electrons. It's like plum pudding the electrons are the plums and the positive charge is the pudding. When two neutrals are rubbed together, after that they each get a separate charge, one positive and the other negative. Negative and positive attract, negative and neutral attract, positive and neutral attract. On Tuesday, we did an experiment to find out which materials could conduct electricity. We found out that metals are conductive. This is a list of materials that are conductive: silver fork, silver plate, foil, copper, iron, brass, pop can and license plate. This is a list of materials that are not conductive: card board, glass and water. We also learned that electricity is the flow of electrons. On Friday, we talked about particle diagrams. We talked of how electrons move through each material, but they have to be conductive. I'm still not sure I get all of this information, but I will caught on eventually.

Blog Week 21

On Monday, we continued practicing with mol problems. My group got question seven from unit five worksheet two. We got the atomic mass for iron, which was 55.8g, but since the substance was Fe2O3 we timed 55.8 x 2 = 111.6g. Then we got the atomic mass for oxygen, which was 16g, then we timed 16 x 3 = 48g because the substance was Fe2O3. After that we added those two numbers together to get 159.6 and that number is the mass for one mol. So, we then set up the equation: 2.50kg x 1000g/1kg x 1mol/159.6g, we added the 1000g/1kg because the masses need to be the same unit, so they could be canceled out. The answer we ended with was 15.7 mol Fe2O3. We then listened to the other groups questions, which were numbers six and eight. They each got the right answers, I did the same problems for extra practice, in the picture below is my work on the problems.

On Tuesday, went over how to do the problems we've been practicing in class. We first talked about turning grams to mols. First you find the molar mass of the substance in question, it relates the grams for every one mol of the substance. We then add up the molar masses of all the atoms in substance. We then came to the conclusion that the equation is: 1mol/mass(g) x g = mol. We then talked about how to turn mol into grams. First you have to find the molar mass and add up all the atoms. We the decided that the equation is: mol x mass(g)/1mol = g. Then we went onto say the equation for mol to molecules is: mol x 6.02x10^23molecules/1mol = molecules. So to get molecules to mol the equation is: molecules x 1mol/6.02x10^23molecules = mol. At the end of class we were introduced to the electrolysis apparatus.
On Wednesday, we had a shortened period, sadly to say goodbye to Mr. Toby. During the class we did an experiment, creating hydrogen and oxygen gases by adding electricity to the system. The information we wanted to obtain was the volumes of each gas, along with mass, molar masses, and mols. I got the measurements and wrote them down, but I wasn't if they were correct. On Thursday, I fixed and my work and my group ended up being correct. The volume of hydrogen was 2 and the volume for oxygen was 1. From their used the densities I looked up on Wednesday, but we had to convert them, because they were in liters not milliliters. We then wanted to find the mass. So for hydrogen this was our equation: m/2 = 89.88, m = 0.1798g. Then equation for oxygen's mass was: m/1 = 1.429g. Then we needed to find the mols. So we had the molar masses, which are the atomic masses and since it was H2 and O2, we multiplied the molar masses by two. So, hydrogen's molar mass was 2.02 and oxygen's molar mass was 32g. To get mols we set up the equations for oxygen and hydrogen. Oxygen's equation was: 1/32 x 1,429 = .0447 mol. Hydrogen's equation was: 1/2.02 x 89.99 = .089mol. Which proved that water was H2O a 2 to 1 ratio. You called it the empirical formula. You said based on the mass we can find mol, then find the ratio and then the formula. (I hope I all the numbers are right, you told us we needed to divide by a 1000 instead of multiply by 1000, so I hope I fixed it right.) This picture below shows my groups data. The one on the right is the set up of the experiment.

On Friday, we took an assessment. I didn't really like taking it on my phone. I guess I'm old fashioned in my test taking. I prefer to do my tests on paper. I think I did ok on the assessment, but some questions were really confusing.