Lab

We had a lab the other day, and we were working with copper sulfide. When you heat this chemical, it changes from blue to white, eliminating the water in it. The masses change when heated. It wasn't the most exciting lab but I'm glad I got the opportunity to do it.

Quiz

The quiz we took the other day was not easy. It required a lot of math, and I got confused about how to set up some of the problems. Hopefully the test on Monday will be better than the quiz, but I got a lot of studying ahead of me.


here's a link to help with calculating formulas of hydrates
https://www.youtube.com/watch?v=KCuYQ3ayFNM

Test

Today we had our test over chapter 2 and 5. It wasn't that easy for me, but then again it never really is! It doesn't help that I fell asleep on my book while studying, but at least I got some sleep right? The test was over matter, sig figs, and dimensional analysis. There were some questions that I got confused on, but hopefully I didn't fail.

Scientific Notation

 In class the other day, we were taught ( or reminded) how to do scientific notation. I think it looks confusing, but once you do one, it's pretty easy. Lets say you have the number 0.0804. With this number, you would have to move the decimal to the right until there is one significant figure to the left of it. So you would move the decimal two spots over, in-between the 8 and the 0 to the right of it. So the new number would be 8.04. We times this number by ten because when you move the decimal over, you are multiplying it by 10 or -10. In this case, we are multiplying it by -10 since it is moving to the right. The scientific notation of this number would be 10 x 8.04 -2  ( the two is suppose to be an exponent) 

Matter Notes

Today in class we breezed by chapter two, talking about matter. Matter is anything that takes up space, and it comes in three forms, solid, liquid, and gas. Take water for example, to change it from a liquid to a gas, you would have to raise the temperature to do so. Raising the temperature also increases the kinetic energy.
          We also talked about physical properties, which can be observed without changing a substance into another substance. An example is boiling water, and the density of something.
          There is also chemical properties, which can only be observed when a substance is changed into another substance. An example of this is flammability.

Half Life

Half life is defined as the time it takes for a half of the sample to decay into a stable form. For example, if you start off with 100 grams of a sample, and the half life is two days, in two days you will have 50 grams, the next two you will have 25, and so on.
            We did a lab on half life, we had to figure out who the missing person was by figuring out how long they have been dead. For this experiment, we cut up little pieces of paper and then dumped them out from a cup. The one facing up we took out, they demonstrated the atoms that have been decayed in the first half life. Each half life took ten years; we repeated this six more times. With this information, we found out who was missing.

Radioactive Decay

There are three kinds of radioactive decay, Alpha decay, Beta decay, and Gamma decay. Alpha decay always has a helium nucleus, it has a mas number of four and an atomic mass of negative two. Beta decay is when a neutron changes into a proton, its mass number remains unchanged and its atomic number adds one. Gamma decay has no change in both its mass number and atomic number. It always accompanies alpha and beta decay. So even when a decay formula doesn't have gamma listed, we know it's there, it's just not implied.