Quiz 3 results and Molecular weight

Hello everyone!  I hope your weekend went well and last week's quiz went well for all students.  On to another week we go and there is a lot of great information to be learned this week!

For Students:
Quiz answers are as follows:
1.  .319 Kilograms = 3190 grams
2.  3.19 micrograms = .00000319 grams
3.  3190 centigrams = .003190 Mega grams
4.  31.9 grams = 31900000000000 pico grams
5.  31900 milligrams = .0319 kilograms

6.  3 moles of hydrogen atoms = 18.06 *10^23 hyrdogen atoms
7.  3.01 *10^23 protons = 1/2 a mole (.5) moles of protons
8.  23 moles of electrons = 138.46 *10^23 electrons
9.  4.56 * 10^ 29 oxygen atoms = 7.57 *10^5
10.  The mole is also called??  Avagadro's Number

Hope everyone did well!  This week we will learn what the molecular weight of an element is and how to use Avagradro's number to determine how much mass of something we have.  The atomic weight (also called the molecular weight) of an element is the average mass of a representative sample of atoms.  Atoms with the same atomic number but a different mass are called isotopes.  Since the atomic number is the same, we know that the number of protons is the same.  Also, since electrons do not add a significant amount of weight in an element, the particle that must be changing is the nuetrons.  Nuetrons are the nuetral particles in the nucleus of atoms that do nothing really except change the weight of an atom.  Some examples are shown below:



For Parents:

FYI:  Most students in the class are doing very well.  The class average as of today is a B+ and 12 students currently have an A or A-.  There are only 2 students with D's and no one is failing at this time.  We will be doing another experiment next week on density.  The students themselves will be handling this as there is no chemicals involved.  Thanks for all the help at home!  The kids and I really appreciate it!

What is a Mole?

What is a Mole?

Is it an animal that lives underground?  No!  It is a very important number that is used by chemists and physicists everyday.  The mole is equal to 6.02 x 10^23.  That is to say that 6.02 x 10^23 of anything; particles, atoms, electrons, etc. is in one mole of that substance.  So if you have 1 mole of hydrogen atoms, then you have 6.02 x 10^23 hydrogen atoms!  The number itself is technically equal to the number of atoms in .012 kg of carbon 12.  The incredibly important number is also called Avagadro's number.  It is named after Amedeo Avagadro:

This famous chemists was responsible for Avagadro's Law which states that an ideal gas with the same temperature, pressure and volume contains the same number of molecules, regardless of which gas it is.  This was very important for the development of chemistry!

Students:

We will begin to learn how to convert between moles and number of atoms or particles.  This will allow us to find the weight and or the number of atoms in a certain amount of something.  The quiz on friday will include some of these type conversions and some of the conversions we started last week; going from grams to kilograms, liters to milliliters, etc.  Please study!



Grade Tracker Instructions

Students:
Here are the instructions I promised for the grade tracker assignment.  This assignment is more for your benefit than mine, but I would like to see that you have done it by this Friday.  Please email me your grade tracker no later than Friday night.  Thanks!

grade tracker

Metric Prefixes and More

Two weeks done and two quizzes finished.  We will be starting to learn metric prefixes this upcoming week and begin to discuss balancing equations.  This week will also be our first in class experiment!  It will be a demonstration only, but it will give the class some ideas of how we go about doing experiments and how to see what you are learning about science from them.

For Students:
Answers to this weeks quiz are as follows:
   1.  32 degrees Fahrenheit =     0 degrees Celsius   (this should have been an easy one!)
   2.  11 degrees Celsius =     51.8 degrees Fahrenheit  (52 is acceptable)
   3.  15 degrees Fahrenheit =    -9.44 degress Celsius
   4.  26 degrees Celsius =   299 Kelvin
   5.  55 degrees Fahrenheit =    285.78 Kelvin (286 or 285.8 is acceptable)
   6.  44 degrees Celsius =    111.2 degrees Fahrenheit  (111 is fine)
   7.  90 degrees Fahrenheit =    305.2 Kelvin (305)
   8.  312 Kelvin =  39 degrees Celsius
   9.  312 Kelvin = 102.2 degrees Fahrenheit
  10.  What is absolute zero?      273 Kelvin

We will next to talking about the metric system and its prefixes.  Every country in the world except the US uses the metric system and we use it in science.  It is a more convenient method because everything works in powers of ten.

Please begin to look at these prefixes, they might be on our next quiz!  (hint, hint)  Also please be able to draw a bohr model of an atom, labeling the protons, nuetrons, and electrons.

For Parents:

The simple experiment we will be doing in class is really just an exercise in the scientific method.  This will get the students used to doing experiments using the scientific method.  The lab report will simply be a write up of the 7 or so steps involved in the scientific method.  I will be asking students if a piece of paper can be burned twice.  It will be something like this...

Hopefully, everything goes well with this!  Again, if your child need help, please instruct them to see me after school.  I have still had very few visits, so hopefully that means everyone understands!  Have a great week!

Today's weather is 275.8 Kelvin!

Good afternoon to you all!

Today's weather is a mild 275.8 Kelvin.  Is that cold or warm????   It is also 2.8 degrees Celsius and/or 37 degrees Farenheit.  So, it's warmer than it was yesterday, but get ready.... tomorrow should be around 269.1 Kelvin, -3.9 degrees celsius or 25 degrees fahrenheit!  Whew!

For Students:
Did you know how to do the above conversions??  Can you go from fahrenheit to celsius to Kelvin scale??  In case you forgot, the formulas (which need to be memorized) are:

Celsius = 5/9 (F - 32)

Fahrenheit = (9/5xC) + 32

Kelvin = 273 + celsius

Remember that fahrenheit and celsius are given in degrees, but Kelvin is given in Kelvins.

This is the Bohr model of an atom.  We will discuss in the next few days why this model isn't correct, but why we use it anyway.  We will also learn what an atom really looks like.  Also, we will discuss the different fundamental particles in the atom.  These are the three smallest particles that exist on their own.  First, is the proton, which gets a positive charge (+1) and exists inside the nucleus of the atom.  Second, is the nuetron, which gets no charge (nuetral) and also exists in the nucleus.  Orbiting around the nucleus are electrons, which get a negative charge (-1).  These electrons are not actually tiny flying particles, flying randomly around the nucleus.  Electrons are actually waves inside an atom and they radiate away from the nucleus in discrete, fundamental places.  If you could see electrons in an atom, they would be fuzzy clouds, not flying particles!



For Parents:

How much do you know about atoms? When I was first taught about atomic structure, I was taught the basic model of particle electrons flying in circular orbits around the nucleus.  Science is always changing, and we now know so much more about what atoms really look like.  We even know that protons and nuetrons can be broken down into even smaller particles!  The field of science is never considered "finished".  It is always being re-written and revised as we discover new and exciting things.  It is the most fascinating subject to teach!

First Week of School

Hello!  I hope everyone had a great first week of school.  I enjoyed all my classes and I feel that I have a great group of kids this year!

For Students:
I hope that first quiz didn't scare you too much!  Since there are no make up quizzes needed in the class, the answers are as follows:
           1.  He = Helium
           2.  C = Carbon
           3.  Ne = Neon
           4.  H = Hydrogen
           5.  Na = Sodium
           6.  Mg = Magnesium
           7.  Mn = Manganese
           8.  Fe = Iron
           9.  Cu = Copper
          10.  Si = Silicon
          11.  S = Selenium
          12.  K = Potassium
          13. Zn = Zinc
          14.  Au = Gold
          15.  Ag = Silver

I hope you all did well.  Graded quizzes will be returned on Monday.  For this week I would like you all to start thinking about units of measure.  In chemistry we use the SI system of measure.  We will start this week talking about length, mass and time.  Also we will learn about the Kelvin and the man responsible for setting up this absolute temperature scale, Lord Kelvin.

For Parents:
Our first quiz this week went well and there were a lot of good scores!  Please continue to ensure your student does well by asking how their quiz went and if they understand our current material.  As I said before, I always stay at least and hour after school for students if they need help.  No one came by this week, so I assume everyone understands.  Thanks for all your support!

Welcome Students and Parents!!

Hello and welcome to Introductory Chemistry.  Please check this blog periodically for important information and updates.  I am Erin Clement and I have a bachelor's degree in secondary education, with a focus on chemistry.  I have always wanted to teach and after my second year in college I realized what it was I wanted to teach.  My goal this semester is to help young people see how interesting and fun science can really be!  I want everyone to see the value in not only chemistry but science in general.

For Students:

This is a periodic table.  It is something you should become very familiar with.  Take it with you.  Take it to your sports practice.  Take it on dates.  Take it to bed and put it under your pillow at night.  We will be going over this in great detail and some of it will be on your first quiz.  The periodic table was created by many scientists but a man by the name of Dmitri Mendeleev is credited with it's creation.  Mendeleev's genius was to discover a pattern to the mess of elements.  Elements in the same row have similiar characteristics and also elements down the same row have similar characteristics.  Mendeleev was actually able to predict elements that were not yet discovered by arranging the elements this way.

For Parents:

We will be having a quiz every Friday.  I will return the graded quizzes on Monday, so be sure to check with your child about how they are doing.  I will be available everyday after school for individual help, if it is needed.  Please, advise your child to seek help if they need it.  I want everyone to succeed!