Testing the Wordle....

Molecular Shapes

Hello!  I hope everyone had a great week and a great quiz!  The answers for Friday's quiz are as follows:

1.  Draw the Lewis Dot Structure for Calcium Chloride:

2.  Draw the Lewis Dot Structure for water

3.  Draw the Lewis Dot Structure for COCL2 indicating formal charges

4.  Draw all resonance structures for Sulfur Trioxide

I hope you all did well!  One reason for drawing Lewis electron dot structures is to be able to predict the three-dimensional geometry of molecules and ions.  Because the physical and chemical properties of compounds are tied to their structures, the importance of this subject cannot be overstated.  The valence shall electron-pair repulsion (VSEPR) model is a reliable method for predicting the shapes of covalent molecules and polyatomic ions.  Simply put, electrons want to stay as far away from other electrons as possible.  The simplest way to understand this model is to assume the electron pairs around the central atom are involved in only single covalent bonds.  These follow a AXn formatting where A is the central atom and X is the atoms connected to the center atom with n being the number of these atoms connected.  Here are some basic shapes:

Linear = AX2

Trigonal-planar = AX3

Tetrahedral = AX4

Trigonal bipyramidal = AX5

Octahderal = AX6

I would suggest studying these.... hint.... hint.....  Remember this is only if the central atom is surrounded by single bonds!

For Parents:

We will be having our science project fair in a month.  All students are required to pick a topic that is chemistry related, but can't be dangerous.  Some good ideas can be found at this web site : Chemistry project ideas.  Please have your child pick a topic by this Friday.  Thanks!





Formal Charges and Resonance in Lewis Structures

For Students:
Today we are going to discuss two important features of Lewis dot structures.  The first is called the formal charge.  The formal charge is given to an individual atom in a molecule or polyatomic ion.

The sum of the formal charges for the atoms in a species equals the overall charge on the ion or is zero (for an uncharged molecule).  The formal charge for an atom is calculated based on the Lewis structure.
Formal charge = group number of atom - (LPE + 1/2(BE))
In this equation LPE stands for the number of lone pair electrons on an atom and BE is the number of bonding electrons around the atom.
So in the above example for the top oxygen on the left molecule, the formal charge = 6 (group number) - (2 (lone pair) + 1/2(6) (bonding electrons))----> which is 6 - (2+3) = 1.  That is why there is a + above the atom.

Next, what happens when you come up with two different ways to write a Lewis structure, and both ways are correct?

This is called resonance, and was first proposed by Linus Pauling.  Resonance structures are used to represent bonding in a molecule or ion when a single Lewis structure fails to describe accurately the actual electronic structure.  Resonance structures differ only in the assignment of electron-pair positions, never atom positions.  Also, there will always be at least one multiple bond in each resonance structure.

For Parents:
We will be having another exam in 3 weeks.  Be sure that your child understand all the material we will be going over.  This is the section of the course that gets difficult and I am more than happy to help anyone who needs it.  Thanks!

Quiz results and the begining of bonding and molecular structure

For Students:
The quiz results are as follows:
1.  Chromium = 1s2 2s2 2p6 3s2 3p6 3d5 4s1
2.  What is the maximum number of electrons that can be identified with each of the following sets of quantum numbers?
a.  n = 4, l = 3 ml = 1 1/2? --> 2
b.  n = 6, l = 1, ml = -1, ms = -1/2  --> 1
c.  n = 3, l = 3, ml = -3  -->  none because l cannot equal n

3.  Arrange the following atoms in order of increasing ionization energy: Si, K, P, and Ca
K < Ca < Si < P

The picture shown above is called a Lewis dot structure.  These are for CH4, C2H4 and C2H2.  Structure refers to the way atoms are arranged in space, and bonding describes the forces that hold adjacent atoms together.  When a chemical reaction occurs between two atoms, their valence electrons are reorganized so that a net attractive force - a chemical bond - occurs between atoms.  There are two general types of bonds.  Ionic bonds form when one or more valence electrons are transferred from one atom to another, creating positive and negative ions.   In contrast, a covalent bond involves sharing of valence electrons between atoms.

The american chemist Gilbert Newton Lewis introduced a useful way to represent electrons in the valence shell of an atom.  The element's symbol represents the atomic nucleus together with the core electrons.  Up to four valence electrons, represented by dots, are placed one at a time around the symbol; then, if any valence electrons remain, they are paired with ones already there.  These pictures are refered to as Lewis electron dot symbols, and the pictures above are great examples!

For Parents:

The exam last week went very well.  The average grade was a B-, which is quite good!  If your child did not receive the grade they wanted or if there is something they don't understand, please have them come and see me.  Thanks again for all you do!

Atomic properties and periodic trends...

For Students:

The picture shown above gives and more or less accurate depiction of the atomic size trends going across the periodic table.  As you can see the largest atoms are in the bottom left of the periodic table.  Francium must be huge!  It is one of the biggest atoms, but not really huge, remember that atoms are approximately 10^-11 m in diameter.

Next we will look at electron affinity which is the energy required to add an electron to an atom in the gas phase.  In other words, how much that atom resists aquiring a new electron.

As you can see atoms in the top right corner really don't want any more electrons.  Helium is not going to be taking on any more electrons any time soon.  And this make sense because helium's shell is already full and it would have to make a new shell to hold any more electrons.  This would take a huge amount of energy to do!
Finally we will look at ionization energy which is the amount of energy required to remove an electron from a particular atom in its gas state.

It is essentially the same as the electron affinity but you have to remember that for electron affinity the values are getting more and more negative as you move up and right in the periodic table.  The energy required to add an electron is negative if something really resists it.  The ionization energy goes up when you move up and right in the periodic table in a positive way.  This means that it would require more and more energy to remove an electron  as you move up and right.

For Parents:
There will be a quiz tomorrow instead of Friday and on Friday we will be having our 2nd test of the semester.  Please make sure your child understand what is going on and please have them ask questions if they don't understand something on the study quide.  Hopefully things go well Friday!  Thanks!

Aufbau and Hund!

For Students:
Today we are going to discuss the other two very important principles to understand when it comes to doing orbital box diagrams.  Last time we discussed Pauli's principle, which states that no two electrons in an atom can have the same 4 quantum numbers.  When doing an orbital box diagram, another thing you should remember is the aufbau principle.  Aufbau literally means "building up".  The idea is to keep the energy in an atom as low as possible.  If you start at the bottom of our box diagram and fill in electrons from the bottom up, then you are essentially keeping the energy as low as possible.  (Remember that the box diagram has the lowest energy at the bottom and increases energy levels as you move up).    The final rule to remember is called Hund's rule.  Simply stated, this rule says that, for example in a p row of your energy orbital diagram, you should fill in the first three electrons, one in each box, all with the same spin first.  Then, you can fill in the boxes with the next 3 electrons, with the opposite spin.  Since this may sound a little confusing, lets look at some examples of all three rules for orbital box diagrams put together:

1.  Nitrogen would look like:

2.  Carbon would look like:

This is an idea of how to do these....

For Parents:

The second exam is next week.  I have sent home study guides today, so make sure if your child needs any help; have them come see me.  Have a great week!



The structure of atoms and periodic trends.

Hello!  I hope everyone had a great weekend.  This week we begin to develop some ideas about what the quantum numbers mean.
For Students:
Here are the answers to last week's quiz:
1.  Which of the following radiation involves less energy, x-rays or microwaves?  microwaves
2.  Place the following types of radiation in order of increasing energy per photon?
fm station < yellow light < x-rays
3.  An electron moves with a velocity of 2.5 x 10^8 cm/s.  What is its wavelength?
.29 nanometers
4.  How many subshells occur in the electron shell with the principal quantum number n=4?
four
5.  State which of the following orbitals cannot exist according to the quantum theory?
2d and 3f orbitals can't exist (n=2 subshell can only have a s or p subshell and n=3 can only have s, p or d subshells)

I hope everyone did well.  We now move on to new material.  To make the quantum theory work, the Austrian physicist Wolfgang Pauli stated in 1925 his exclusion principle: no two electrons in an atom can have the same four quantum numbers.  The result of this is that no more than two electrons can be in the same orbital.  One with an "up" charge and one with a "down" charge.  We will depict this using orbital box diagrams:

For example, when you want to depict the two electrons that make up a helium atom you would start at the bottom level, the 1S level and draw one arrow up and one arrow down inside the box.  That tells us that you have two electons in the 1S orbital, one spinning in the positive direction and one spinning in the negative direction.  Please note that these directions are completely arbitrary, it just helps us understand that there can't be two identical electrons in an atom.  Also it is important to note that s orbitals have one box, p orbitals have 3 boxes and d orbitals have 5 boxes.  How many boxes do you think an f orbital would have??  Seven is right!  The order of increasing energy must be memorized.  This will be on your next quiz.  The order is (starting at the bottom and working our way up): 1S, 2S, 2P, 2S,3P,3D, 4S, 4P, etc.

For Parents:
There have been a few difficulties lately regarding significant figures and scientific notation.  An error in this regard will not make the answer to a problem wrong, but I will have to start taking off a point of two.  If your child needs help in this area I will be available after school as usual and I will be giving out a review sheet to help with this.  If you have any questions let me know.  Thanks and have a great day!

No quiz last week, lucky you!

For Students:
You all know that we didn't have a quiz last Friday due to the field trip on Wendesday and the assembly Friday afternoon.  Don't get used to that!  Another one is coming up this Friday.
Anyway, this week we will be talking about quantum numbers and orbitals (and what that means for us chemists).  Quantum numbers are used to identify the energy states and orbitals (paths around the nucleus) available to electrons.  There are three principle quantum numbers.  The first is called the principal quantum number and its symbol is n.  The principle quantum number can have any whole number value from 1 to infinity.  It is the primary factor in determining the energy of an orbital and it defines the size of the orbital.  If more than one electron in an atom has the same (n) number, they are said to be in the same shell.  Shells can be broken down into subshells as well.  The second quantum number is called the azimuthal quantum number and its symbol is l.  This quantum number determines the actual shape of the orbital and it can have any whole number value from 0 to n-1.

If l = 0, you have an s orbital.

If l = 1, you have a p orbital.

If l = 2, you have a d orbital

And finally, if l = 3, you have an f orbital.

Our last quantum number is called the magnetic quantum number and it has the symbol m.  This number refers to the orientation in space of the orbitals within a subshell.  You can see from the above pictures that an s orbital can be oriented in just one way.  P orbitals can be oriented in 3 ways, d orbitals in 5 ways and f orbitals in 7 ways.  The magnetic quantum number can have the value of -l to l.

So now you can visualize exactly where the electrons have a good probability of being located around the nucleus.



For Parents:

Grades are looking very good so far this semester.  If you or your child have any questions don't hesitate to ask.  You can post on this blog, write me an email or see me after class everyday until 4:30pm.  Thanks again!





Field Trip Success!

Today was our field trip to the great lakes science center!  We learned a lot and had a lot of fun.  But, now it's time to focus on this weeks lessons....

For Students:

How does wave-particle duality affect our model of the arrangement of electrons in atoms??  So far we have discussed the simplistic version of a model of an atom with a nucelus, composed of protons and nuetrons and electrons orbiting around it.  In Bohr's model of the atom, both the energy and location for the electrons in the atom can be described accurately.  But, this is merely a simple view of what the atom really looks like.  Werner Heisenberg and Max Born came up with the idea that, for something as tiny as an electron, and given that the electron has wave and particle properties, any attempt to determine accurately either the location or the energy will leave the other uncertain.  In other words, you can definately know an electrons location or it's energy, but not both at the same time.  This is now known as Heisenberg's uncertainty principle.

The importance of this idea is that we can asses only the likelihood or the probability of finding an electron with a given energy within a given region of space.  This is the basis of quantum mechanics... next time we will discuss quantum numbers and orbitals!

For Parents:

The field trip was a great success.

The great lakes science center is a great place for schools and families alike.  If you have not visited it, I would highly recommend it!



Introduction to Quantum Mechanics

For Students:
Answers to this weeks quiz are as follows:
1.  A frequency of 2.45 gigahertz has what wavelength in meters?
    (2.45 gigahertz = 2.45 x 10^9 Hertz)  c = wavelength x frequency,  wavelength = c/f
     = .122 m
2.  Which color in the visible spectrum has the highest frequency? = violet
3.  Which color in the visible spectrum has the highest wavelength = red
4.  Which is longer the wavelength of a microwave or a radio wave? = radio
5.  what is the speed of all electromagnetic radiation? = 3.00 x 10^8 m/s

Next we are going to be talking briefly on quantum mechanics and how it relates to chemistry.  We have already talked about how electrons and light both exhibit particle-wave duality.  They both can act like a wave or a particle, in certain circumstances. 

This man is Louis Victor de Broglie and he proposed that a free electron (not attached to any atom) with a mass m moving with a velocity v, should have an associated wavelength.  His equation, wavelength = h/mv is very usefull in many chemistry problems.  The h in this equation is a constant, called Planck's constant, and is named after Max Planck.  It's value is 6.626 x 10^-34 J/sec.  Remember that light and electrons behave like particles and waves, but not simultaneously.  In a given situation, they will behave like either a particle or a wave.  We will talk more about the de Broglie equation and wave-particle duality this week.

For Parents:

Wednesday is the big day!  Field trip day!  We are planning to see and do everything and we should have a lot of fun.  Make sure your child arrives to school on time on Wednesday as we will leave promptly at 8:30 am.  Also, be sure your child has a bagged lunch.  Thanks for all your help!



Shifting gears

Can you believe we are in the 6th week of school already?  It seems like we just started, but it sure is going fast.  Only 12 weeks left, and still so much to cover.  We are going to be leaving the subject of heat and energy for now, and we are moving on to a more in depth look at the structure of atoms....

The is the aurora borealis, or northern lights.  These beautifull colors are caused by electrons in the solar wind bumping into molecules in the upper atmosphere.  This make the molecules excited and they emit light. 
The colors seen can be white to red, green, orange, and others.  Different colors mean different things, like wavelenths (light travels in waves), energy, etc.

For Students:

Most of our understanding of atomic structure comes from a knowledge of how atoms interact with light and how excited atoms and molecules emit light .  In order to understand atomic structure, we will first look at electromagnetic radiation.  Electromagnetic radiation really is just waves of electric and magnetic fields working together.  In 1864 a man by the name of James Clerk Maxwell created a theory to describe these waves.  He proposed that electric fields produce magnetic fields and changing magnetic fields produce electric fields.  Two important properties of waves are its wavelength and its frequency.  A wavelength is symbolized by the greek letter lambda: and it is the distance between successive crests of a wave.  A frequency is symbolized by a lower case f and it is the number of cycles per second.  1 cycle per second is equal to a hertz. (Hz).  And finally, the speed of all electromagnetic waves (not just light) is 3.00x10^8.  Wavelength and frequency are related to a waves speed by this equation:

C (m/s) = lambda (m) x f(s^-1)

C = 

X Frequency

For Parents:

Thanks for your prompt attention to the permission slips.  Our field trip is next week!

Quiz results and more about energy!

For Students:
Hello!  Hopefully everyone's quiz this week went well.  The answers are as follows:
1.  How much energy must be transferred to raise the temperature of a cup of coffee (250 mL) from 20.5 C to 95.6 C.  Assume water and coffee have the same denisty and specific heat capacity (4.184 J/g*K)?
       change in T = 368.8 K - 293.7 K = 74.1 K
       q = C x m x (change in) T
       q = (4.184)(250)(75.1)
       q = 79,000 J or 79kJ

2.  An 88.5 g piece of iron whose temp. is 78.8 C is placed in a beaker containing 244 g of water at 18.8 C.  When thermal equilibrium is reached, what is the final temp.?
       q(metal) = q(water)
       (C (water) x m(water) x (change in temp.)) = (C(Fe) x m(Fe) x (change in temp.))
       (4.184 x 244 x (T(final) - 292K) = (.449 x 88.5 x (T(final) - 352K)
       T (final) = 295K or 22 C

The two above photos show two very important temperatures for water, and for other substances as well.  Everything has a melting and a boiling point.  The energy transferred as heat that is required to convert the substance from a sold at its melting point to a liquid is called the heat of fusion.  On the other hand, the energy transferred as a heat to convert a liquid at its boiling point to a vapor is called the heat of vaporization.  These values are constants for a particular substance and a table with some common values can be found in the back of your book.  It is important to recognize that the temperature remains the same throughout a change of state.  These types of situations will be discussed this week.

For Parents:
Hopefully everyone received their permission slip for our upcoming field trip to the Great Lakes Science Center.  Permission slips must be returned by Friday.  Remember, students will need a bagged lunch on the day of our trip.  Thanks and have a great week.!

Heating and Cooling in reactons

Happy Wednesday everyone!  This semester is steadily rolling along and I think everything is going quite well.  This week we will be talking about heating and cooling and specific heat capacity.

For Students:
We can't talk about specific heat capacity without first talking about the unit of energy, (remember heat is a form of energy), the joule.  The joule is name for James Joule:

Joule was the son of a wealthy brewer in Manchester, England.  The family wealth and the workshop in the brewery gave Joule the opportunity to pursue scientific studies.  Among the topics that he studied was the issue of whether heat was a massless fluid.  He eventually figured out exactly the nature of heat!
The calories in the food you eat are actually measured in Kilocalories, which is 1000 calories.  A calorie (not a kilocalorie) is equal to 4.184 joules.
When an object is heated or cooled, the quantity of energy transferred depends on three things:
1.  the quantity of the material
2.  the amount of temperature change
3.  the material itself
Specific heat capacity (c) is the energy transferred as heat that is required to raise the temperature of 1 gram of a substance by 1 kelvin.  The units are joules/g*k (joules per gram kelvin).   For solving these types of problems, first you need to find the change in temperature.  This is the final temperature - the initial temperature.  It is given in Kelvins.  Then you need the formula:
                                    q (heat) = C (specific heat) x m (mass) x change in temperature

We will be working on these this week!

For Parents:
I mentioned the field trip and it is coming!  We will be going to the Great Lakes Science Center in 3 weeks.  You should be seeing a permission slip home this Friday.  Your student must pack a bag lunch and can bring money for the gift shop if you'd like.  We will be leaving school at exactly 9 am and returning at 2 pm.
Great Lakes Science Center

Thanks again, and have a nice day!

Energy and Chemical Reactions

What makes this hot air balloon rise?  Actually, a propane burner heats the air inside the balllon until the air is heated enough to be less dense than the air outside, causing it to rise.  Energy in the form of heat is needed to make this work.  Similarly, energy (usually in the form of heat) is needed in many chemical reactions.

For Students:
The science of heat and work is called thermodynamics.  This week we will be learning about the relationships between energy changes, heat and work.  We will also be talking about how we can determine whether a chemical reaction is product favored or reactant favored.  Energy can be defined as kinetic or potential.  Kinetic energy is the energy of motion, it can describe the motion of atoms, molecules, a moving tennis ball, or automobile.  Basically anything moving in anyway has kinetic energy.  Potential energy is stored energy and is directly related to an object's position.  Holding a ball at the top of a waterfall has potential energy and so does energy stored in fuels.  Finally, the Law of Conservation of energy states that energy can neither be created or destroyed.  Energy is always constant, it can remain the same or change forms, but the amount of energy in the universe is always constant.
The answers to last week's quiz are:
1.  OH-    -->  hydroxide
2.  Cyanide  -->  CN-
3.  Carbonate  -->  CO3 (-2)
4.  nitrite  --> NO2 (-)
5.  PO4 (-3) --> phosphate
6.  NO3 (-) --> nitrate
7.  SO3 (-2) --> sulfite
8.  CLO (-) --> hypochlorite
9.  sulfate --> SO4 (-2)
10.  chlorite --> CLO2 (-)
11.  chlorate --> CLO3 (-)
12.  perchlorate --> CLO4 (-)
13.  CrO4 (-2) --> chromate
14.  CH3CO2 (-) --> acetate
14.  MnO4 (-) --> permanganate
15.  HCO3 (-) --> bicarbonate

Hope everyone did well!

For Parents:
The quiz grades seem to be slipping a bit, so just a reminder: if your child needs help please instruct them to see me after school or during lunch break.  I am always willing to help!  Also, FYI  we will be going on a field trip to the Great Lakes Science Center in Cleveland.  This trip is still a few weeks away and permission slips will be going home soon.  Thanks again for all you do!

Naming Ionic Compounds

For Students:
So far we have talked about molecular compounds.  Ionic compounds are another major class of compounds.  They are made up of ions, which are atoms or groups of atoms that bear a positive or negative charge.  Many familiar compounds are composed of ions.  Table salt (NaCL) and lime (CaO) are just two examples.  In order to recognize ionic compounds and to easily write formulas for these compounds, it is important to know the formulas and charges of common ions.  You also need to know the names of ions and be able to name the compounds they form.  Unfortunately, this is something that must be memorized.  Ions are composed of two different types.
Cations are atoms that lose an electron (or two, etc.)  Losing an electron give a positive charge so all cations have a positive charge.   Some examples are Li+ and Ca +2.  Elements on the left side of the periodic table typically are cations.  The left two columns are the most common.
Anions generally have a negative charge due to the gaining of one or more electrons.  An example is O -2.

These ions can be monatomic (single atoms) or polyatomic (two or more atoms).  The following are common polyatomic ions that should be memorized:

For Parents:

The density experiment is this week and before we begin to learn what different materials' densities are, we will be watching this fun video:



Have a great week and don't forget, Density = mass/volume!

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!