Electron configuration... yes boring title i agree too...

silicon is 1s22s22p63s23p2

DOES THAT MAKE ANY SENSE TO YOU?
IF NOT PLEASE CALL 1-800-NED-CHEM THERE YOU WILL GET ALL.
okay time to get REAL serious.

So what does this electron configuration mean? its basically how each electron is place in an atom.

So there are 2 numbers one is energy Level and the other is number of electrons in that energy level and orbital
Energy level is the number in the front "n" and the energy difference between 2 energy levels is called quantum of energy. COOOL quantum... = =.
now there is this thing called ground state and excited state.
ground mean its stable and will most likely not do some random explosion.
excited means its excited... imagine an excited person.. what will he/her? yea jump around and that is what the electron does too... it jumps.. to the lower shell to gain stability and become ground. In this process it releases energy..SO MUCH TALKING BORING...
Orbital = region of space used by an electron in an energy level s.p.d.f
Shell = a group that have the same orbital and n value the 1.2.3.4.5.6.7 # in the front
Subshell = the s p d f thing that are in the same shell like 1s 1p 1d 1f but they contain different numbers of electron
in n=1 shell there can only be s type
n=2 is s and p type
n=3 is s p d type
n=4 s p d f type

all s type subshell can have 1 s orbital
p have 3 p orbitals
d have 5 d orbitals
f have 7 f orbitals

and each orbital can have 2 electrons...
IN CONCLUSION
s subshell can have 2 electron
p have 6
d have 10
f have 14

Higher "n" number = less stability.. and = more energy release when it get excited and jump that's why the uuu stuff can only live for a millisecond

this is boring right?
i agree...

the order is 1s 2s 2p 3s 3p 4s 3d 4p 5s 4d 5p 6s 4f 5d 6p
7s 5f 6d 7p... BUT THAT IS LIKE NERD LEVEL MEMORIZATION
so normal people like me who isn't no-life science person use the
awesome graph of love

and yes this is as easy as it gets.

Electron always fill from the lowest.. so THERE WILL ALWAYS BE 1 + electron in 1s if u don't have 1s something is wrong...
Also electrons likes to be by themselves instead of pairs... so ALWAYS ^ ^ ^ and then v v v (yes i know they are v's... to bad)
negative Ion just means its full shell it will be like the next noble gas easy yes
positive ion isn't so cool... if its +5 you have to take away 5 electrons and if there are electron in s and p orbitals p is removed first (plz don't ask why only some random chem nerd will be able to answer you that)

by this point you are probably wondering why I'm not finish yet... (yea i know life suck i got a long blog live and read plz, apparently we learned a lot today so too bad...)
Okay now Core notation
Core Notation = above row NOBLE GAS + Valance electron config and yes this makes your life easier... BUT the teacher can be mean and make you write Uranium and make you write in stander form lovely isn't it?

WE ARE ALMOST DONE

now we got 2 bad boys Cr and Cu they are bad because THEY START WITH C don't confuse with Cs which stands for counter strike or Cd... or Dy just because people aren't that smart these days

All ions and noble gas have full valence shells the + - sign on the atom means - means its needs w/e amount of electron
+ mean it needs to get rid of w/e amount of electrons
example Ag [Kr] 4d10 5s1 and Ag ion will be [Kr] 4d10

also there is this open and close shell thing...
open = not full still open...
close = to bad no more electron is accepted and is close for business.. = full shell...

Examples
U uranium?? electron config??? STANDER FORM YES I AM MEAN
okay i give u answer... just incase your teacher give u this...

1s2,2s2 2p6,3s2 3p6 3d10, 4s2 4p6 4d10, 5s2,5p6 5d10 5f3, 6s2 6p6 6d1, 7s2
this is torture mode
normal mode.. [Rn] 5f3 6d1 7s²... OMG SO MUCH SHORTER

okay Ga is next

1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p1
core is [Ar] 4s2 3d10 4p1
yea now its ion is since its +3 so you have to get rid of 3 electron and always start from p then to s so answer
[Ar] 3d10 too bad no stander form its happy so yay and stable..

like electron config can't really have really weird questions so just pick random element from periodic table and write the electron config.. REMEMBER CR CU!!! THEY = EVIL

always end with youtube yes

Atomic Structure

OK. Long story short: Theres this thing called an atom, inside are electrons and a nucleus. Inside the nucleus we have protons and neutrons.

k thanks for reading, bye.







































KIDDING!
OK SO.  Heres the general idea of what an atom looks like as we know today:
Atom ---> Electrons in orbitals in shells + 1 nucleus ----> protons and neutrons ----> quarks (we'll save that for another time)

ANYWHO.... lets start with our 3 main subatomic particles.
The Proton: Charge: +1, Mass: 1 amu or 1.672 * 10^-27 kg,
The Neutron: Charge: 0, Mass: 1 amu or 1.674 * 10^-27 kg
both of these particles are located within the nucleus. Though the neutron has a slighty larger mass, we still count it as 1 amu
The Electron: Charge: -1, Mass: 0 amu or 9.11 * 10^-31 kg
these particles are located in orbiting shells around the nucleus. The mass is deemed so small that we use a 0 amu.

NOW.. we move on to the different properties of atoms.
Atoms are either neutral of charged.
A neutral atom is said to have equal amounts of protons and electrons therefore balancing out the charge.
A charged atom is called an ion. It will have lower or higher amounts of electrons than protons
If there are more electrons, the atom is negatively charged and deemed an anion
If there are less electrons, it will be positively charged and deemed a cation

Mass Number:
This is the total mass of an atom in amu.
Calculated by # of protons + # of neutrons

Atomic Mass:
the average atomic mass of the different isotopes of an element
isotopes: elements have different masses depending on the number of neutrons they have
for example: uranium-235 and uranium 236. By adding 1 neutron to uranium-235, you'll get uranium-236. This turns a stable atom into an unstable atom that has the potential to create nuclear explosions.

The mass number and atomic mass are similar but not the same. When working with molar calculations, we usually refer to the atomic mass. BUT HOW TO FIND AVERAGE MOLAR MASS???? HMM???

ex. Hypothetical element X exists as 67.24% X-23 (23.251) and 32.76% X-24 (24.446). What is the average molar mass of hypothetical elemt X?

We simply average it out like so:

(0.6724)(23.251) + (0.3276)(24.446) = 23.64

Atomic Theory

Yay, atomic theory. What it is? I will tell you.

Atomic theory is a theory of the nature of the atom (Greek: atmos) which is the smallest pieces of matter
       Aristotle believed in the four elements: fire, water, earth and air
       Alchemists believed they could turn metal into gold

But this was not a scientific theory because it could not be proved with observation

One of the first greek philosphers who mentioned atoms was Democritus in 300 B.C. He thought that they were idivisible particles Hmm interesting.'



After Democritus, Lavoisier in the late 1700's introduced the Law of Conservatino of Mass and Definite Porportions



Next came Proust (1799) and he proved Lavoisiers' Laws by experiments.

Dalton came after in the 1800's and he stated that atoms are solid, indestructable spheres. Based on the Law of Conservation of Mass



There were still many things that werent discovered but later on in the 1850's J.J. Thomson discovered that atoms had positive and negative charges.



In 1905,  Rutherford shows that atoms have a positive, dense center with electrons and suggested that atoms are mostly empty space.



Neils Bohr (1885-1962), studied gaseous sample of atoms which were made to glow by passing through an electric current. He proposed that electrons surrounded the nucleus in specific "energy levels" or "shells."

This video below will show you a brief timeline of all the scienetists and people that are important. Yeah.

MOST ASWOME LESSON ON PERCENTAGE WHICH WE DIDN"T LEARN IN GRADE 2!!!!! FUN FUN FUN FUN FUN!!

life is like a sign sigh.

Yay after the long break we finally start learning again.. fun…..

Don’t have much time so Less random stuff sorry~ and of course we all still remember the super fun and exciting lab right?

Okay~ we are doing Percent Yield and Percent Purity

So what is Percent Yield and Percent Purity Percent yield is found by dividing the actual mass of product formed by the mass of the product expected hmm what does this mean? It means that Percent yield is how much stuff will be produced when 2 chemicals are reacted together so what percentage of thing is actually formed.

Percent Purity on the other hand is the percent of a specified compound or element in an impure sample. So out of the big chunk of rocks how much of it is actually useful? Only the useful stuff reacts.

Okie examples…

3Mg(OH)2 + 2H3PO4 H Mg3(PO4)2 + 6H2O

Q1 Calculate the mass of Mg3(PO4)2 that will be formed (100% yield) from the

reaction of 15.0 g of 92.5% Mg(OH)2 with an excess of H3PO4.

13.875g Mg(OH)2 * 1 mole Mg(OH)2/ 1 mole Mg(OH)2 * 1 mole Mg3(PO4) 2/ 3 moles Mg(OH)2 * 262.9 g Mg3(PO4)2/ 1 mole Mg3(PO4)2 = 20.9 g Mg3(PO4)2   (typing that took years)

Q2 Calculate the mass of 88.5% Mg(OH)2 needed to make 127 g of Mg3(PO4)2, assuming a

100% yield.

Gold ore

127 g Mg3(PO4)2 x1 mole Mg3(PO4)2 / 262.9 g Mg3(PO4)2 *  3 moles Mg(OH)2 / 1 mole Mg3(PO4)2  *  58.3 g Mg(OH)2 / 1 mole Mg(OH)2   = 84.49 g Mg(OH)2.

Okay Percent Yield Question

CaC03 ---> Ca0 + C02
If 50kg of Calcium carbonate is used, and 21kg of calcium oxide is made, what is the percentage yield of the reaction?

The reaction is OMG I don’t know how to do this…  Jokes…

50 kg CaCO3 x (1000 g CaCO3 / 1 kg CaCO3) x (1 mole CaCO3/ 100.09 g CaCO3) x (1 mole CaO / 1 mole CaCO3) / (56.08 g CaO / 1 mole CaO) x (1 kg CaO/ 1000 g CaO) = 28.015 kg CaO

Hahahah you see how the Kg part screwed everyone over? XD

21 kg / 28 kg = 75% yield

a chinese dude teaching win!

http://misterguch.brinkster.net/pra_equationworksheets.html

god level site for chemistry!

some lab thing..........you work with another pair......yay

ummm yea.....we had a lab....sooo fun.. 6D to be precise.  This experiment is unique in that it takes 2 days to do it.  The purpose of this is to determine which reactant is limiting and which is excess.

ok we wore our super cool stuff.  Then we obtained 2 reactants known as Na2Co3 and Cacl2.  We weighed them both and then  we combined them in a 25ml beaker and waited for 5 minutes.  We probably waited for 13 min and 42 sec but whos counting?  Anyway we then set up a ringstand with a paper funnel in the hole of the ringstand( must be folded triangularly bro and weighed).  underneath the filter paper was a clean beaker.  We then poured our 13 min and 42 sec combined solution into the filter paper and waited....and waited...for like 18min and 21 sec.  Then we found out we had a murky white substance in the beaker and some left over residue in the paper funnel.  We then saved our filter paper to weigh next time.  From our experiment we can conclude we had an excess and limiting reactant!!

yea i had to do this

 Na2CO3 + CaCl2 ---> CaCO3 + 2NaCl
this is the reaction and when we weigh the precipitate left behind in the filter paper we can determine which reactant is excess and which is limiting and by how much! omg so exciting






This is how you fold the filter paper

Limiting and Excess Reactants

OK party people let MC JayLiu drop these beats on excess and limiting reactants

NO, that was NOT lame. In fact it's what all the fly kids by saying these days. Word

OKAY. So we see two terms from the title alone. Excess and limiting reactants? Let me put it in a way that most people can relate to.

Let's say for some unknown reason you want to make me a sandwich. Ingredients and supply? BREAD 10 pieces. SALAMI 489 slices. My sandwich consists of two pieces of bread with 267 slices of salami in between, no more, no less.

When we take a look at our bread supply, we see that we have to make five sandwiches. GREAT! Let's make 5 sandwiches.

HALT, EVIL DOER!

LOOK AGAIN, and you will see that we have a mere 489 slices of salami, enough to make 1 sandwich.

Therefore: only 1 sandwich can be made due to a LIMITING supply of salami, even though we have EXCESS bread. Also, JayLiu's 4th law of stoichiometry: One can never have EXCESS salami.

like this, without all that green crap

NOW, let's move away from the art of sandwich craft and move to ACTUAL Stoichiometry.

Eg. Butane burns in the presence of oxygen to form carbon dioxide and water. If 12.0g of butane reacted with 46.0g of oxygen, which reactant is excess/limiting and how many grams of CO2 will be produced?

STEP 1: WRITE THE EQUATION AND BALANCE

2 C4H10 + 13 O2 ------> 8 CO2 + 10 H2O

STEP 2: CONVERT ONE MASS INTO THE OTHER

(12.0g C4H10)(1 mol C4H10/58g C4H10)(13 mol O2/2 mol C4H10)(32g O2/1 mol O2) = 43.0g O2

since 43.0g < 46.0g, C4H10 is the limiting reactant by 3g

STEP 3: USING LIMITING REACTANT, FIND PRODUCT

(12.0g C4H10)(1 mol C4H10/58g C4H10)(4 mol CO2/1 mol C4H10)(44g CO2/1 mol CO2) = 36.4g CO2

Not the first video that appears when searching the query: "limiting and excess reactants".... the second

Molarity and Stoichiometry

This is an add-on from the previous blog.
This add-on costs $19.99
If you purchase this add-on you will be one step closer in reaching your Stoichiometriness.

BUY NOW

Aight, since you bought this add-on you will learn about Molarity.

Lets start with some examples

Eg. How many grams of Calcium will be formed when 100mL of 0.500M CuSO4 is reacted with sufficient Ca?

FIRST Make the equation
1 CuSO4 + 1 Ca ----> 1 CaSO4 + 1 Cu
Second Check if it is balanced
Now convert mL to L and convert to moles
0.100 L x 0.500Mol CuSO4
                ---------------- = 0.05 moles CuSO4
                         1 L
Now convert moles of CuSO4 to moles of Ca

0.05 mol CuSO4 x 1 mol Ca
                              ----------             =   0.05 moles
                              1 mol CuSO4
Now convert moles of Ca to grams by multiplying by the molar mass of Ca

0.05 mol Ca x 40.1g Ca
                       ---------    =   2.005 grams (REMEMBER SIG FIGS) =  2 grams
                       1 mol Ca

Here is a video to help you



Another part of your add-onn is
GAS STOICHIOMETRY (STP)

Here is an example of a gas stoichiometry problem

Zinc Carbonate decomposes into CO2 and Zinc Oxide. How many grams of ZnCo3 are needed to produce 8.0L of CO2 measured at STP?

First make your equation and balance it
1 ZnCO3 ---> 1 CO2 + 1 ZnO

Then convert litres into moles of CO2 to moles of ZnCO3

8.0L x 1 mol C02           1 mol ZnCo3    
           -----------      x   -------------- =   0.35714 moles ZnCO3
           22.4L CO2          1 mol Co2
NOW convert moles of ZnCo3 to grams

0.35714 mol ZnCo3 x  125.4 g ZnCO3
                                    ----------------  =  44.785356g ZnCO3 Round to sig figs 45g ZnCO3
                                      1 mol ZnCO

If you are still having some problems, please visit this website for more info
http://www.chemtutor.com/xmol2.htm