Interesting Story!

 I was looking for a cool story that relates to Chemistry, and I do believe I found something! I knew that books tend to spell the older the get, but I never knew why. Thanks to this article in The Naked Scientists called 'Smell Test for Old Books.' As it turns out, the volatile organic compounds that paper releases builds up like acids which increase as the paper gets older and older.

Not only did I find out why older books give off a certain smell, I also found a website that is filled with fun articles!
To read this article in full, here is the URL : http://www.thenakedscientists.com/HTML/content/news/news/1851/

To get to The Naked Scientist main page, here is the URL:http://www.thenakedscientists.com/HTML/content/news/

Scientific notation and significant figures

Last week my Chemistry class reviewed scientific notation (S.C.) and significant figures (S.F.). I used to think that you could only use scientific notation with whole numbers, but I now know that you can use this notation with decimals as well! Scientific notation makes writing really big or small numbers easy.

Scientific notation

Let's start with whole numbers. An example of a whole number in S.C. looks like this:85000000 = 8.5 x 10^7.

The first thing you need to do is count from the right side until you get to the first number (it takes 7 times to get to the first number, 8)

Next, you put a decimal after the first number and then leave all number behind (unless it's a zero), so it looks like this: 8.5

Then, you add ' x 10' after 8.5, so it looks like this: 8.5 x 10.

Now, remember when you had to count how many times it took to get to the 8? Well, that number (7) is the final part to scientific notation! You simply add ^7 right after the 8.5 x 10, so the finish product looks like this : 8.5 x 10^7.

For finding scientific notation for decimals, you do the same process for finding whole number S.C. The only two differences are that you start from the left side and that the exponent is negative. For example: 0.000253 = 2.35 x 10 ^-4. So, you start on the left side and it take 4 times until the decimal is after the 2. You have a negative exponent because you are coming from the left.

Significant figures

Now, finding significant figures means the numbers that matter in a calculation. To find S.F. is simple, just use the America, Pacific and Atlantic ocean!

The Pacific Ocean is used for decimals, (the P stands for period) and the Atlantic Ocean is used for whole numbers (the A stands for absent a period). The first thing you have to do is figure out if the number is a decimal or whole number.

The example I'll use is 22. This number will be on the Atlantic side, which means you'll have to start on the right side of the number and count the numbers (not including zeros). So, 22 has 2 S.F.

If there is a number like 4572630001, you still start on the right side and since the number 1 is the first number and the zeros come after 1, you will count the zeros as well. So, this number has a total of 10 S.F.


The example I'll use for the Pacific side will be1.085. This number has a total for 4 S.F. To figure out how many S.F. a decimal has, you start on the left side of the number and count. For 1.085, there are 4 numbers, so the S.F. is 4

If there is a number like 0.009, you still start on the left side, but don't count until you get to a number other then 0. This leaves us will 9, meaning that 0.009 only has 1 S.F.

Finding protons, electrons and neutrons!

This week in Chemistry, we learned how to identify the number of protons, electrons and neutrons an element has. I knew beforehand, that the number of protons is the same as the number of electrons, but I forgot where to find the protons at. After, I learned where to find the number for protons - the atomic number. We also had to find the number of neutrons, to which I had no idea how to do. After, I learned that the number of neutrons equals the atomic mass and to find that is to add the protons and the neutrons together.

We also learned how to find the protons and electrons of an ion. To find the protons is easy - identify the atomic number. However, to find the electrons is different; you have to either add or subtract the number of protons. For example, if the element sulfur has the symbol 2-, then you have 2 more electrons than protons. So, you just add 2 to 16 (number of protons), which equals 18 (number of electrons)! Another example is if the element potassium has the symbol 1+, then the means that the electrons are one less than the protons. So, you subtract 1 from 19 (number of protons), which equals 18 (number of electrons)!

 From all that I have learned, I still have a remaining question: how do I find the charge of an ion?

Interesting fact: Did you know that a glass window is actually a liquid, not a solid?

Chemical vs. physical properties

Last week in Chemistry we learned the difference between chemical and physical properties! Now, I knew what a physical property was, but for chemical properties I was totally lost. I used to think that chemical properties were specific, like nitrogen or oxygen. After class, however, I  learned that a chemical property is how something reacts. For instance, when you leave a bike out in the rain, it can start to rust. Rust or oxidizing is a chemical reaction, thus meaning that it's a chemical property. My teacher showed us in this cool demonstration of a chemical property when he lit a helium balloon on fire! This was a chemical property because the chemical in the balloon had a flammable reaction. And that's the end of "chemical vs. physical properties"!

Interesting fact: Did you know that a candle burns approximately at 980 degrees?