Creepy Covalent Bonds (please read the blog. I put a lot of work into it.)

HAPPY HALLOWEEN, EVERYONE... which calls for a special blog. hehehe

{in class: we went over the quiz and took notes. ON Tues.- Outline due and Ch. 5 test. ON Wed.- Ch. 6 quiz. START MEMORIZING THE TABLES 1,2,and 5 ON PGS. 221, 226, AND 230. Dr. B said, "if you want your grades to improve, start now!" Quizes will be taken by tables}

Formation of a Covalent Bond

• Most atoms (and zombies) have a lower Potential Energy when they are bonded with other atoms (or zombies) than when the atom/zombie is alone.
• The chart in our book on pg. 179 shows the P.E. changes during formation of H-H bond

(SHE ALWAYS ASKS QUESTIONS ABOUT THIS CHART!!!)

• Suppose you have two atoms: the electron of one atom ATTRACTS the proton of the other atom (like kids and candy)
• in these same atoms, the electrons in the different atoms REPEL each other (same with the protons) (like candy and evil dentists)

--> These forces cancel out to form a covalent bond where the P.E. is lowest (they are chained together for eternity!!!!!! or until something breaks them up...)

Characteristics of a Covalent Bond

(VOCAB ALERT!)

• bond length- the distance between two bonded atoms at the minimum P.E.

--> The average distance between two bonded atoms

• Atoms release energy forming covalent bonds (like a mummy released from the grave!)
• The same amount of energy must be added to separate the atoms (stuff that mummy back in the grave! haha Take that mummies!)

(VOCAB ALERT!)

• bond energy- the energy required to break a chemical bond and form isolated atoms

• Shared electrons of two atoms in a covalent bond form overlapping orbitals

--> atoms are jealous of noble gases, so they want to make their outer shells like a noble gas's (then they can overthrow the noble gases and rule the periodic table muahaha!)

ex.- two bonded H atoms (with the overlapping orbitals) can each have He's electron configuration

The Octet Rule

• the reason noble gases are unreactive is because their electron configuration is esp. stable

--> stability comes from full s and p orbitals

• Covalent bonding allows other atoms to reach this stability

(IMPORTANTE!!!)

• OCTET RULE- Chemical compounds tend to form sa that each atom, by gaining, losing, or sharing electrons, has an octet in its highest energy level

[THIS RULE APPLIES ONLY TO THE MAIN GROUP ELEMENTS IN THE 2ND PERIOD AND BELOW]

(ALSO IMPORTANTE!!!)

• There are exceptions to the octet rule!- any atoms that can't fit 8 electrons or can fit more than 8 electrons in its outermost energy shell
• the exceptions are- ARGGGGGGGGGGGGHHHHHHHHHHHHHHHHH! (the writer of this blog was dragged away by disgruntled zombies, an evil dentist, mummies, and jealous elements)

(we will cover what the exceptions are on Monday)

Chemical Bonding

Chapter VI: Chemical Bonding
10/29/09

NOTES:
Ionic bonding- chemical bonding that results from the electrical attraction between cations and ations

Covalent bonding- bonds that result from sharing of electron pairs between two atoms

• Nonpolar Covalent Bond- two atoms of same size bond
• Polar Covalent Bond- an atom bonds with an atom of a different size

Percentage Ionic Character-

• To find, subtract the electronegativity of two elements, then find the difference on the percentage ionic character.
• If 0-.3, then it's nonpolar covalent
• If .4-1.7, then it's polar covalent
• if 1.8-3.3, then it's ionic

Molecular Compounds

• a molecule is a neutral group of atoms that are held togethor by covalent bonds
• a chemical compound whose simplest units are molecules is a molecular compound
• the composition of compound is given by its chemical formula
• a chemical formula indicates the relative numbers of atoms of each kind in a chemical compound by using atomic symbols and numerical subscripts.
• a molecular formula shows the types and numbers of atoms combined in a single molecule of a molecular compound

Extra notes: Chapter 5 Test will be on Tuesday, November 3rd; The Chapter 5 outline will be due on the day of the test, Tuesday. Have a good afternoon.

10/28/09

The electrons in te both the cations and anions are in higher energy levels as one reads down a group.

There is a gradual increase of ionic radii down a group

Valence Elctrons

Chemical compunds for because electrons are lost, gained, orshared between atoms

The electrons that interacts in this manner are those in the highest energy level

The electrons available to be lost, gained, or shared in the formation of chemical compundsare referred to as valence elctrons

Valence electrons are often located in the incompletely filled main-enrgy levels

Example: The electron lost from the 3s sublevel of Na to form Na+ is a valence electon

Electronegativity

Valence electrons hold atoms togehter in chemical compounds

In many cmpounds, the negative charge of the valence eectron is concentrted closer to one atom than to another

Electronegativit is a measure of the ability of an atom in a chemical compound to attract electrons from another atom in the compound

Electronegatvities tend to increase across periods and decrease or remain about the same down a group

Need to Know on the Periodic Table

Groups 1 and 2

Inner T.M

Main Group(s&p)

Halogens(17)

Noble gases(18)

Metals(+ ions)

Nonmetals(-ions)

Metaloids

Atomic radius increase from bottom up and right to left

Ionization energy incrreases from bottom to top and left to right

Electron affinity increases bottom to top and left to right

Electronegativity increases bottom to top and left to right

ions!

(+) Cations smaller than original atom

(-) Anions larger than originl atoms

Chapter 3

Electron Affinity

• The energy change that occurs when an electron is acquired by a neutral atom is called that atom's electron affinity
• Electron affinity generally increases across periods
• Increasing nuclear charge along the same sublevel attracts electrons more strongly
• Electron affinity generally increases down groups
• The larger an atom's electron cloud is, the farther away its outer electron are from its nucleus

Ionic Radii

• A positive ion is known as a cation
• The formation of a cation by the loss of one or more electrons always leads to a decrease in atomic radius
• The electron cloud becomes smaller
• The remaining electrons are drawn closer to the nucleus by its unbalanced positive charge
• A negative ion is known as an anion
• The formation of an anion by the addition of one or more electrons always leads to an increase in ionic radius
• Cationic and anionic radii decrease across a period

10-26-09

Regarding the dart lab: It's due Thursday. Use a line graph for the graphs. Clarity is important; neatness isn't. If you had hits outside of the circle, add a row for >10cm, calculate the area of the sheet of paper (remember to convert inches to centimeters), and add your data. Hits are infinitely significant for calculations. The figure on the sheet is not the one from you book. Use Fig. 11 on page 107.

Atomic Radii

• The boundaries of an atom are fuzzy, and an atom's radius can vary under different conditions.
• To compare different atomic radii, they must be measured under specific conditions.
• Atomic radius may be defined as one-half the distance between the nuclei of identical atoms that are bonded together.
• Atoms tend to be smaller the farther to the right they are found across a period.
• The trend to smaller atoms across a period is caused by the increasing positive charge of the nucleus, which attracts electrons toward the nucleus.
• Atoms tend to be larger the farther down in a group they are found.
• The trend to larger atoms down a group is caused by the increasing size of the electron cloud around an atom as the number of electron sublevels increases.

Sample Problem E

Of the elements Mg, Cl, Na, and P, which has the largest atomic radius? Highlight for answer. Na. All of these elements are in the same period, and Na is right-most.

Ionization Energy

• An ion is an atom of group of bonded atoms that has a positive or negative charge.
• Na, for example, easily loses an electron to form Na+.
• Any process that results in the formation of an ion is referred to as ionization.
• The energy required to remove one electron from a neutral atom of an element is the ionization energy, IE (or first ionization energy, IE1).
• In general, ionization energies of the main-group elements increase across each period.
• This increase is caused by increasing nuclear charge.
• A higher level charge more strongly attracts electrons in the same energy level.
• Among the main-group elements, ionization energies generally decrease down the group.
• Electrons removed from atoms of each succeeding element in a group are in higher energy levels, farther from the nucleus.
• The electrons are removed more easily.

P.S. Since I'm such a nice guy, I'll give somebody a chance to volunteer to do the blog tomorrow. If nobody does, I'm going to pick somebody using a random number generator, so no whining if luck doesn't favor you.

10/22/09

We have a lab tommorow
-Each person in the group drops it 50 times at shoulder length with arm extended
-Record where it sticks in the target after each drop
-If it doesn't go through the paper, mark an x where it hit
-You decide whether it is in or out if it lands on a line
-Don't poke people with the darts (Ben).

Notes
-The 3d sublevel is higher in energy than the 4s sublevel, so they are filled in the order
4s3d
-D Block metals are typically have metallic properties and are often referred to as
transition elements
-P Block elements consist of all the elements of Groups 13-18 except helium.
-The p Block elements together with the s Block elements are called the main-group
elements
-Properties of elements of the p Block vary greatly.
-At it's right hand-end, the p Block includes all of the nonmetals except hydrogen
and helium
-All 6 of the metalloids are also in the p Block
-At the left-hand side and bottom of the block, there are 8 p Block metals.
-The elements of group 17 are known as the halogens
-flourine, chlorine, bromine, iodine, and astatine
-The halogens are the most reactive nonmetals
-They react vigourously with most metals to form examples of the type of
compound known as salts
-The metalloids, or semiconducting elements, are located between nonmetals and metals in
the p Block
-The metals of the p Block are generally harder and denser than the s Block alkaline earth
metals, but softer and less dense than the d Block metals
-In the periodic table, the f Block elements are wedged between Groups 3 and 4 in the
sixth and seventh periods
-Their position reflects the fact that they involve the filling of the 4f sublevel.
-The first row of the f Block, the lanthanides, are shiny metals similar in reactivity to the
Group 2 alkaline metals
-The second row of the f Block, the actinides, are between actinium and rutherfordium.
These actinides are all radioactive.

Ch.5 Sec 1 and 2

Ch. 5 Sec 1

1. Periodic Table

• An arrangements of the elements in order of their atomic number so that elements w/ similar properties fall in same column or group
• Elements are arranged vertically in the P.T.(periodic table) in groups that share similar chemical properties

Ch. 5 sec. 2

Periods

• Elemts organized horizontally in rows
• Length of each period is determined by # of electrons that can occupy the sublevels being filled in that period
• The P.T. is divided in 4 blocks, s p d & f; the name of each block is chosen by the electron sublevel being filled in that block (disregarding Hydrogen and Helium b/c they are too small)

Alkali metals

• Elements of group 1 on P.T.
• Lithium, Sodium, potassium, rubidium, cesium, and francium are the Alkali metals
• In alkali metals's pure state, they all have a silvery appearance and are soft enough to cut w/ a knife

Alkaline-earth metals

• Elements in group 2 of P.T.
• Beryllium, magnesium, calcium, strontium, barium, and radium (all Alkaline-earth metals)
• Less reactive than alkali metals, but are still too reactive to be found in nature in pure form

• Hydrogen has an electron configuration of 1s1 but despite the ns2 configuration, it doesn't share the same properties as elements of group 1
• Hydrogen is an unique elments

• Like the Group 2 elements, helium has an ns2 group configurtaion, yet it is part of group 18
• B/c its highest occupied energy level is filled by 2 electrons, helium posses special chemical stability

P.S. remember to do Pre-Lab for tomorrow

10/19/09

Test Tomorrow

• 43 questions
• 6 calculations the rest are conceptual questions
• 100% Scantron
• know the vocab
• know all the scientists and their experiments

Sample Problems from class (there is no option for super and subscript so I will separate with commas)

Ge- 1s2,2s2,2p6,3s2,3p6,4s2,3d10,4p6,5s2,4d9; [Ar]4s2,3d10,4p2

Mn- 1s2,2s2,2p6,3s2,3p6,4s2,3d5;[Ar]4s2,3d5

Ag- 1s2,2s2,2s6,3s2,3p6,4s2,3d10,4p2;[Kr]4d10,5s1

K- 1s2,2s2,2p6,3s2,3p6,4s1;[Ar]4s1

B- 1s2,2s2,2p1;[He]2s2,2p1

Ca2+ --> 1s2,2s2,2p6,3s2,3p6

Br- ----> 1s2,2s2,2p6,3s2,3p6,4s2,3d10,4p6

C4- -----> 1s2,2s2,2p6

Cu2+ ----> 1s2,2s2,2p6,3s2,3p6,4s0,3d10

Al3+ -----> 1s2,2s2,2p6

K ---> n=4; l=0; m=0; s=+1/2

Cu2+ ---> n=4; l=2; m=+1; s=-1/2

Mendeleev and Chemical Periodicity

Mendeleev noticed that when the elements are arranged in order of increasing atomic mass, certain similarities in chemical properties appeared at regular intervals

repeating patterns referred to as PERIODIC

Mendeleev created a table in which elements with similar properties were grouped together----> a periodic table (or chart) of elements

After Mendeleev placed all the known elements in the table there were several empty spaces

1871--> Mendeleev predicted the existence and properties of elements that would fill in 3 of the empty spaces

by 1886---> all 3 of those elements were discovered

Moseley and Periodic Law

In 1911, English scientist Henry Moseley discovered that elements fit into patterns better when they are arranged according to atomic #

Periodic Law-->states that physical and chemical properties of elements are periodic functions of the atomic #s

Chapter 3

Law of Conservation of Mass--Established in 1789 by French Chemist Antoine Lavoisier; States that mass is neither created nor destroyed in any ordinary chemical reaction.

Law of Definite Proportions--a given chemical compound always contains the same elements in the same fixed proportion by mass

Law of Multiple Propotions--statement that when two elements combine with each other to form more than one compound, the weights of one element that combine with a fixed weight of the other are in a ratio of small whole numbers

atomic number--the number of protons in the nucleus of an atom.

atomic mass unit (amu)--a unit of mass that is exactly 1/12 the mass of a carbon-12 atom; also 1 gram/ Avogadro's number

mole--the SI unit used to measure the amount of a substance whose number of particles is the same as the number of atoms of carbon in exactly 12 g of carbon-12

Avogadro's Number--6.0221415 x 10^23

Molar Mass--the mass in grams of 1 mol of a substance

Cathode Ray Experiment

When investigators passed a current through the Cathode tube, they noticed that the surface directly opposite the cathode glowed. They hypothesized that the glow was caused by a stream of particles. They also noticed that the ray was deflected by a magnet much like an electric current was. The rays were deflected to a positive charge and away from a negative charge. This led them to believe that there was a certain type of particle that was being emitted. This was supported when J.J. Thomson found that the particles mass in the cathode tube was always the same, even when the metals where changed. Thomson concluded that all of the cathode rays were composed of the same particles, electrons.

Oil-Drop Experiment

Milikan's experiment was used to find the charge of an e-. Using an atomiser, Milikan put oil droplets in a chamber with a hole at the bottom. Some of the droplets fall through a hole in the bottom. Once though this hole, the droplets are exposed to radiation and attach themselves to free e- in the air. Then, two plates at the top and bottom have current passed through them. The top plate is negative. Milikan determined the charge of an e- by the droplets' abilities to overcome gravity when the charge of the top plate was high enough. An e- has a charge of 1.60217646 × 10-19 coulombs.

Rutherford's Gold Foil Experiment

Ernest Rutherford and his associates bombarded a strip of gold foil with fast moving alpha particles. Geiger and Marsden assumed that the partles would pass through the foil with only a small deflection. However, 1 in 8000 particles was actually deflected directly back at the alpha source. This led Rutherford to conclude that the atom was mostly empty space with most of its mass concentrated at a central point, which he called the nucleus.

Chapter 4

Electromagnetic Radiation--the energy associated with electric and magnetic fields; it varies periodically and travels at the speed of light

Electromagnetic Spectrum--range of all possible frequencies of electromagnetic radiation

Wavelength--the distance over which the wave's shape repeats

Frequency--how many waves are made per time interval, measured in Hertz (Hz)

Photoelectric effect--when light shines on a metal surface, the surface emits electrons

Ground State--The condition of an atom, ion, or molecule, when all of its electrons are in their lowest possible energy levels

Excited State--A stationary state of higher energy than the lowest stationary state or ground state of a particle or system of particles

Line-Emission Spectrum--relative intensity of electromagnetic radiation of each frequency emitted by atoms or molecules of that element or compound when they are excited

Heisenberg Uncertainty Priniciple--The position and momentum of a particle cannot be simultaneously measured with arbitrarily high precision

Orbital-- the probability distribution of an electron in a atom or molecule

Principal Quantum Number--indicates the main energy level occupied by the e-

Angular Momentum Quantum Number--indicates the shape of the orbital

Magnetic Quantum Number--indicates the orientation of the orbital around the nucleus

Spin Quantum Number--indicates the fundamental spin states of the e-

Aufbau Principle--an e- occupies the lowest energy orbital that can receive it

Pauli Exclusion Principle--no two e- can have the same set of quantum numbers

Hund's Rule--orbitals of equal energy are each occupied by one e- before any orbital is occupied by a second e- and all e- in singly occupied orbitals must have the same spin

Noble Gas--a family of nonreactive monoatomic gases found on the far right of the periodic table

Noble Gas Configuration--shortened version of electron configuration in which you simply include the closest noble gas (of a smaller atomic number) and list the electron configuration from the next element from the noble gas to the element you are doing the configuration for

The Photo-Electric Effect

In the early 1900s, scientist conducted two experiments that had results that could not be explained by the wave theory of light. One was the Photo-Electric Effect. Scientists observed that even at high intesities, a metal would not emit an electron unless the frequency was correct. This contradicted the theory that light of any frequency could supply enough energy to eject an e-. Scientists began to think that light wasn't just a wave, that it also had mass.

10/15/09

10/13/09

Today we did a worksheet in class and prepared for our test next tuesday. TEST NEXT TUESDAY. Finish the worksheet for tomorrow

Low energy

• Radio waves
• Microwaves

Medium energy

• Infra red
• Visible light

High energy

• Ultraviolet ----> goes through the magnetic field and is absorbed in ozone field
• Gamma Rays ----> deflected by magnetic field
• Cosmic Rays----> deflected by magnetic field

1m= 1x 10^9nm

Hz= 1/s=s^-1

c=3.00x10^8m/s

h= 6.626x10^-34j(s)

1MHz= 1x 10^6 Hz

1m= 1x 10^6mm

Have fun fellas

Joe's Blog Oct. 13

we turned page 126 in today, it was HW #1

47)E=hv v=E/h = 1.55 x 10^-24 J
________________ = 2.39 x 10^9 Hz
6.626 x 10^-34 J(S)

42) c. they are the same speed

46) e. 3
f. 10

49) Schrodinger used math probabilities to find electrons in a certain area
Bohr said electrons orbit the nucleus much like planets around the sun



Selenium (Se) - configuration for the last electron
1s^2,2s^2,2p^6,3s^2,3p^6,4s^2,3d^10,4p^4

l = 0 ->s
l = 1 -> p
l = 2 -> d

n = 4
l = 1
m = -1
s = -1/2
----------------
Fr
n = 7
l = 0
m = 0
s = +1/2


--------------
Ra
n = 7
l = 0
m = 0
s = -1/2



we can use the TI calculators 83-89 , change the batteries, bring 2 #2 pencils, don't randomely guess.
1.A
2.C
3.D
4.D
5.B
6.B
------
1.C
2.B
3.C
4.B
5.C
6.C
7.c
8.D
9.E
10.B
11.C
12.B
13.D
14A
15.C

Elements

N

1s2 2s2 2p3

[He] 2s2 2p3

2/1s 2/2s 3 1/2p

n=2

l=1

m=1

s=+1/2

He

1s2

1s2

2/1s

n=1

l=0

m=0

s= -1/2

Zn

1s2 2s2 2p6 3s2 3p6 4s2 3d10

[Ar] 4s2 3d10

2/1s2 2/2s2 3 2/2p 2/3s 3 2/3p 2/4s 5 2/3d

n=3

l=2

m=2

s= -1/2

Cr

1s2 2s2 2p6 3s2 3p6 4s1 3d5

[Ar] 3d5 4s1

2/1s 2/2s 3 2/2p 2/3s 3 2/3p 1/4s 5 1/3d

n=3

l=2

m=2

s= +1/2

P

1s 2s2 2p6 3s2 3p3

[Ne] 3s2 3p3

2/1s 2/2s 3 2/3p 2/3s 3 1/3p

n=3

l=1

m=1

s=+1/2

Al

1s2 2s2 2p6 3s2 3p1

[Ne] 3s2 3p1

2/1s 2/2s 3 2/2p 2/3s 1 1/3p

n=3

l=1

m=-1

s=+1/2

Movie Blog

Blog of Movie

• Higgs-Boson particle is infinitely small "god particle" said to give mass to everything
• Fermilab is using the particle accelerator (the Tevatron) to find the Higgs by speeding up protons and smashing them into each other
• As Fermilab draws nearer and nearer CERN is Switzerland builds the LHC a particle a particle accelerator 27 kilometers in circumference
• Fermilab funds are substantially cut by the government putting the Higgs research in terrible danger
• The separator spark in the Tevatron experienced problems and it was shut down for 2 weeks to fix it
• In Summer '06 Fermilab produced 1 inverse femtobarn which is a measure of the gazillions of collisions produced since March '01
• Fall '08 LHC will be up and running
• Fermilab is looking for the Higgs at 115-135GeV
• They developed e- cooling which makes more antiprotons which means more collisions
• CERN has 7x more energy making it hard for the LHC to find the "light Higgs"
• The bump of data John's group previously found, which was rumored to be the Higgs, disappeared
• December '07 62 million more is cut from the budget and many scientists are forced to work at CERN

Joe's comment - I think The Higgs particle deserves more attention than it is getting. I think it is a shame that American scientists are forced to go elsewhere to study in their particular field. I think American businesses are already outsourcing enough and now a government funded project is losing money. I think it's wrong.

Blog for 10/6/09.

Is there not a blog for tonight?

LAST BLOG OF THE FIRST QUARTER

Elements of the 5th Period

• In the 18 elements of the 5th period, the sublevels fill similar to the 4th period(see previous blog)

succesive electrons are added first to the 5s sublevel, then the 4d, and finally the 4p.

-if you look at the periodic table, it flows straight across. A video from my comment last Friday explains this.

• Sample Problem B: (a) Write the complete electron configuration and noble gas notation of the semi-cool element. aka-iron (Fe); atomic #= 26 [not as cool as Rubidium, which is in problem C]
• (b) How many electron-containing orbitals are in the semi-cool element iron? How many orbitals are completely filled? How many unpaired electrons are in one atom of iron? What sublevel are the unpaired electrons in?

ANSWERS: (a) [1s2,2s2,2p6,]->10[3s2,3p6,4s2]->10[3d6]-- the 10s are Dr. B's way of grouping electrons so you can keep track of them (they do like to move around a lot)

(b) electron containing orbitals-15 (REMEMBER--s=1 orbital;p=3 orbitals;d=5; and f=7) count them up for each level/ completely filled orbitals-11(you can see this by drawing out the orbital notation aka the arrow-line things)/number of unpaired electrons-4 (all those lonely arrows)/the orbital of the unpaired elecrons-3d (where the lonely electrons are found)

• For more practice with this stuff, check out sample problem C in our book.
• HOMEWORK-#11 P. 125-126 #33-41 AND study for that test on thursday, sounds like a doozy

test help Ch. 3 -p. 88 and 89 in our books

Ch. 4 - p. 123 Dr. B told us to know all the vocab and ideas from the chapter.

If you need help, e-mail Dr. B, search your friendly internet, or just pray to Our Lady of Partial Credit on Thursday

P.S. This blog is in honor of the great Griff "doesn't have a nickname that I know yet" Moran.

Friday, October 2

Electron Configuration Notation

- Electron configuration notation eliminates the lines and arrows of orbital notation

- Instead, the number of electrons in a sublevel is shown by adding a superscript to the sublevel designation

- The helium configuration is represented by 1s²

- The superscript indicates that there are 2 electrons in helium’s 1s orbital

Elements of the Second Period

- In the first period elements, hydrogen and helium, electrons occupy the orbital of the first main energy level

- According to the Aufbau principle, after the 1s orbital is filled, the next electron occupies the s sublevel in the second main energy level

- The highest occupied energy level is the electron-containing main energy level with the highest principal quantum number

- The inner-shell electrons are electrons that are not in the highest occupied energy level

Elements of the Third Period

- After the outer octet is filled in neon, the next electron enters the s sublevel in the n=3 main energy level

- Noble Gas Notation

o The Group 18 elements (Helium, Neon, Argon, Krypton, Xenon, and Radon) are called noble gases

o A noble gas configuration refers to an outer pain energy level occupied, in most cases, by 8 electrons

o Ex. K-19 = [1s²2s²2p⁶3s²3p⁶]4s¹

- = [Ar]4s¹ ← complete electron configuration

o Remember, only noble gases can be placed in brackets

Orbital Box Diagrams

- Uses boxes, putting the correct arrows in the box

- Just like the line and arrow diagram

Elements of the Fourth Period

- The period begins by filling the 4s orbital, the empty orbital of lowest energy

- With the 4s sublevel filled, the 4p and 3d sublevels are the next available vacant orbitals

- The 3d sublevel is lower in energy than the 4p sublevel. Therefore, the five 3d orbitals are next to be filled

- Notable exceptions to this are Copper and Chromium

Electron Configurations

Section 3 Electron Configurations

The order of increasing energy for atomic sub levels is show on the vertical axis on page 111 of the chemistry book. Each individual box represents an orbital.

Rules Governing Electron Configurations

• According to the Aufbau principle, an electron occupies the lowest-energy orbital that can receive it.
• According to the Pauli exclusive principle, no two electrons in the same atom can have the same set for four quantum numbers.
• According to Hund's rule, orbitals of equal energy are each occupied by one electron before any orbital is occupied by a second electron, and all electrons in singly occupied orbitals must have the same spin state.

Representing Electron Configurations

Orbital Notation

• An occupied orbital is represented by a line, with the orbital's name written underneath the line.
• An orbital containing one electron is represented as one arrow pointing in the upright position with a line under it.

• An orbital containing two electrons are represented as one arrow pointing in the upright position(North) and one arrow pointing in the down position(South) with a single line under both.

• The lines are labeled with the principal quantum number and sub level letter. For example, the orbital notation for helium is written as the symbol He to the left of an arrow pointing North and an arrow pointing South with an single line under it having (1s).

P.S. The arrows with (1s) written under it is written similar to a fraction having (He) as the whole number.