General Chemistry
- Alfred Nobel (1833-1896) invented dynamite; his fortune
Chemistry- science of composition, structure, properties and
reactions of matter especially of atomic and molecular systems
matter- anything that has mass and takes up space
- J.W. Hyatt (1837-1920) developed the first plastic
- Leo Baekeland (1863-1944) developed the first synthetic resin
funded the Nobel Prizes in science and humanities
Brief History
- Egyptians used chemical practices to develop techniques for
producing perfumes and dyes that were known as far back as
2600 BC
- Metallurgy is another area of chemistry for refining copper,
gold, iron and meals that they developed for high-quality
materials used in jewellery, decorations and money
- Medicines were also discovered
- The earliest medical textbook consisted of hundreds of clay
tablets found in Mesopotamia from 2600 BC
- Traditional Chinese medicine has records from 350 BC that
describe 240 medical reparations and 150 drug combinations
- Items made from gold have been found in Bulgarian graves
over 7000 years old
Modern Chemistry
Clothing
- fibers such as silk from silkworm and cotton from plants are
natural fibers
Transportation
- metal, plastic, gasoline, oils, fuels
Farming and Gardening
- water purification, nutrient-rich soil chemically analysed,
chemical sprays and soil treatment
Health Care
- drugs, synthesis of new compounds, preparation and use of
surgical materials, clinical tests
Alchemy
- the medieval forerunner of chemistry
- Alchemists were a group of scholars and charlatans that aim to
create the philosopher’s stone a substance that causes the
transmutation of lead into gold and the elixir of life that bestows
immortality of a person who possessed it
- Major branches: Chinese, Indian and European
- Robert Boyle (1637-1691) began his research and made a
__________
Scientific Method
- Greek philosophers also had interests in chemistry
There are two approaches to logical thinking:
• Inductive Reasoning
- Gases were described mathematically
- Formulated idea that small particles combine to form molecules
- Francis Bacon (1561-1626) advocated this use
- first step is to make specific observations
- draw conclusion
- 1700, chemistry developed
- Joseph Priestly (1733-1804) isolated and characterised gases,
- a prediction based on the principle then it will be tested and a
major progress
• Deductive Reasoning
- begins with a general principle that must be true
including carbon monoxide and nitrous oxide, discovered
oxygen
- Nitrous oxide or laughing gas worked as a general anesthetic
and first used in 1844 on tooth extraction
- C.W. Scheele (1742-1786) discovered chlorine
- Antoine Lavoisier (1743-1794) discovered nitrogen, he was
considered as father of chemistry
- John Dalton (1766-1844) expanded it and formed his atomic
theory in 1807
- Avogadro (1776-1856) calculated the number of particles
present in a given amount of gas
- Alessandro Volta (1778-1827) invented battery
- Humphry Davy (1778-1829) and Michael Faraday (1791-1867)
contributed in the areas of theoretical ideas and practical
applications, field of electrochemistry was developed
- Charles Goodyear (1800-1860) discovered the process of
vulcanization which produced a stable rubber
- Louis Pasteur (1822-1896) pioneered the use of heat
sterilization to eliminate unwanted organisms in milk and wine
conclusion can be drawn
1.
2.
3.
4.
Ask a question- identify problem
Make observations- gather data
Propose an explanation or hypothesis for the observations
Design and carry out ways to test hypothesis
-when a hypothesis is confirmed repeatedly through experiments
on different labs, it becomes a theory
-a theory is a general principle that is offered to explain a natural
phenomenon
Phlogiston Theory
- Disproven idea that materials lost phlogiston when they burned
- Phlogiston is a substance, from greek word, which means
burning up)
- Johann Joachim Becher (1635-1682) made phlogiston theory
in 1667
- He had taken greek elements, earth, air, fire and water and
discarded fire and air, expanded the earth to three groups with
one involved in burning
- George Stahl renamed this particular fraction as phlogiston
1
- ex. When woods are burned the ashes remaining after the fire
weighed considerably less than the original wood sample,
therefore, it seemed that phlogiston had been released during
the burning process, leaving the dephlogisticated ashes
behind. If wood was burned in a closed container, the fire would
be extinguished. The theory was that air could only absorb so
much phlogiston, which was later on believed as nitrogen.
- contradiction: when magnesium is heated the product weighs
more that the original magnesium metal, which then offered
that phlogiston had negative weight
- Antoine Lavoisier studied oxygen and found that when mercury
is heated, it would become mercuric oxide and gain weight.
When mercuric oxide is heated, it returned to mercury and
released a gas identified as oxygen.
- This theory was replaced by the oxygen-based combustion
ideas developed
__________
Matter and Change
All types of matter exhibit:
• Chemical properties
- describe the reaction with other substances and they can be
determined by seeing what happens to a substance when it’s
placed in air, water, an acid, a base and other chemicals
- they indicate how the composition of a substance will change
• Physical properties
- used to observe and describe matter
- can be measured without changing the composition of the
matter
- mass, weight, volume, density
• Intensive properties
- Physical properties that do not depend on the amount of
the substance present
- do not change with changes of size, shape or scale
- taste, melting point, boiling point, density, luster,
hardness
- ex. color: Aluminum metal is gray colored
• Extensive properties
- Physical properties that do depend on the amount of
substance present
- mass, volume, length
• Liquid
- Has definite volume but indefinite shape
- Substance adopts the shape of new container when
transferred
- incompressible
• Gas
- Has neither definite shape nor definite volume
- Takes up the shape and volume of its container
- The particles are very far apart from one another that they are
compressible
- Often invisible but can be detected
Pure Substances
-have a constant composition and can be changed through
chemical reactions
-constant composition indicates that a sample of a pure
substance contains the same elements in the same proportions
• elements- substances that can’t be decomposed into
simpler substances by chemical or physical means
• compounds- substances that can be broken down into
elements through chemical means
Periodic Table of elements
-classification and organisation of known elements
-used to know the composition
Mixtures
-when two or more pure substances are combined together
-have variable compositions that indicate that the relative
proportions of the mixture components may vary and can be
separated by physical means
• Homogenous
- the composition is uniform throughout the mixture
- ex. Dissolve a small amount or a large amount of
salt into water. Although the ratio of salt to water
will differ, the mixtures will both be homogenous
- (wine, air and gunpowder) their exact compositions
can vary, making them mixtures rather than pure
substances
• Heterogenous
- Have distinguishable parts
- Exists in solid or liquid states but not gas because
the particles are freely mix
- Quite common like in oil-and-vinegar dressing or
soil
- Compositions vary
Classification of Matter
- the states (solid, liquid and gas) of a given substance is a
physical property
• Solid
- Has a definite shape and volume, and does not change when
transferred form one container to another
- The particles are packed tightly and almost completely
incompressible but when heated or cooled, it expands or
contracts slightly
2
• Chemical Change
- Chemical reaction in which chemical identity of a
substance is altered
- ex. Burning of woods, rusting or corrosion, rotting,
fermenting
- photosynthesis, cellular respiration
- Involves combination, decomposition or rearrangement
of elements and compounds to form new substances
- Chemical property describes the ability of substances to
undergo chemical change
- Happens when there’s a change in color, a gas is
__________
produced, a solid product called a precipitate is produce,
a change of energy is apparent due to a change in temp
or the appearance of light
Changes in Matter
• Physical Change
- A change in the form
- Chemical changes involve a transfer of energy (same
with physical) but to check, test composition of the
substance after change has occurred
- Used to separate mixtures into their components
Chromatography
- Separation of mixture by passing it through a
medium in which the components move at different
rates
- Mixtures that are solutions, suspensions or even
vapors
- ex. Paper chromatography can be used for
separating mixtures in which one or more are
colored (dyes)
Distillation
- Separate mixtures comprised of two or more liquid
(ex. separating out a homogenous mixture)
- purification process in which components of a
liquid mixture are vaporized (liquid to gas) and then
condensed (gas to liquid) and isolated
- Mixture is gradually heated
- Solutions with lowest boiling point will change into
gas first, then passes through a cooled tube
(condenser) where it condenses back to liquid
- Condensed liquid is called distillate
Evaporation
- Separate homogenous mixtures in which one or
more solids are dissolved in a liquid
- Mixture is heated until all of the liquid has
vaporized, leaving behind dissolved solids
- This vapor can be captured and re-condensed into
liquid
- Only used to separate volatile liquid components
__________
Measurement
-some quantities measured in chem are distance (length),
volume, mass, time, velocity, temp, density, pressure, amount,
concentration, energy and electric charge
-should compare, contrast, categorise and analyse
Systeme International (SI)- common metric system of units
Base Units
- Physical details
- Have own independent scale and can’t be expressed in terms
of other base units
- volume, force and energy can be derived from these
Physical quantity
Name of SI unit
Abbreviation
Mass
kilogram
kg
Length
meter
m
Time
second
s or sec
Temp
Kelvin
K
Amount of sub
mole
mol
Electric current
ampere
A
Luminous intensity
candela
Cd
(those which evaporate at low temp) from
nonvolatile solid components (those which will not
evaporate at low temp)
Filtration
- Separate mixtures in which some particles are
large enough to be captured with a porous material
while others are not
- ex. Some water filters can filter bacteria out from
Derived Units
- Combination of base units
stream waters
3
Physical quantity
Name of SI unit
Abbreviation
area
square meter
𝑚2
volume
cubic meter
𝑚3
speed, velocity
meter per sec
m/s
acceleration
meter per sec
squared
𝑚⁄𝑠 2
force
Newton (mass x
acceleration)
N(kg 𝑚/𝑠 2 )
mass identity
Kg per cubic meter
𝑘𝑔/𝑚3
energy
Joule (force x
distance)
J(kg 𝑚2 /𝑠2 )
Magnitude and Scale
- In chem, we measure the size of an atom which is
Dimensional Analysis and Metric System
- Technique that uses the units (dimensions) of the
measurement to convert between units
approximately 1/10000000000 of a meter
- We express size in terms of fractions or multiples of 10
- Prefixes are used to write the unit as a power of 10
- Conversion Factors are used to solve in which certain
Commonly used SI Prefixes
ex. Convert 4.3 cm to μm
1 m= 100 cm
1 m= 106 μm
measurements are expressed in different units
Scientific Notation
- Or exponential notation
- A coefficient and number 10 raised to a power
ex. Distance from earth to sun is about 150,000,000,000 meters
written as 1.5 x 1011 m
- Coefficient must be larger or equal to one and less than 10
ex. A common mosquito weights approximately 0.0000025 kg
Coefficient must be between 1-10
2.5 is the coefficient
Quantity 0.0000025 kg is less than 1, so 10 must be raised to a
negative exponent which will be moved to the right by 6 places
2.5 x 10−6 kg
Adding and Subtracting
-same basic units
ex.
1.235 x 103 meters + 3.45 x 102 meters
4
Convert numbers to regular notion
1235 meters + 345 meters
= 1580 meters
Convert back to scientific notation
- How close a given set of data is to the real value
- Of an estimate can’t be improved through calculation
1.580 x 103 meters
-different base units
ex.
1.5 x 102 liters — 3.45 x 102 deciliters
Convert umbers to regular notion
150 liters — 345 deciliters
Decide on which unit to use
Precision
- How close estimates are to one another
- Values that are relatively close to these averages would be
precise
150 L — 34.5 L= 115.5 L
Convert to scientific notion
1.155 x 102 L
Multiplying and Dividing
-same base units
ex.
(4.65 x 103 meters) x (3.65 x 102 meters)
Group coefficients and exponential terms together
(4.65 x 3.56) x (103 x 102 ) meters x meters
Multiply coefficients and add exponents
(16.55) x (105 ) 𝑚𝑒𝑡𝑒𝑟𝑠 2
Change to scientific notation
1.655 x 106 𝑚2
(when two values are multiplied together, units are multiplied as
well)
Calibration
- Technique to increase accuracy of measurements
- Method of setting or correcting a measuring device by
matching it to known measurement standards
- To standardise devices like meter sticks, graduated cylinders,
scales
ex. Thermometer
-different base units
ex.
(4.65 x 10−4 liters) x (3.65 x 102 milliliters)
Convert to common unit, choose milliliters
- By using freezing and boiling point of water
- If freezing point is at 0°C and boils at 100°C, we can
calibrate by measuring the temperature of ice and boiling
water
- Place in ice water and wait for the thermo liquid to reach
Group coefficients and exponential terms together
a stable height then place a mark at this height which
represents 0°C, place in boiling water, and after waiting
for the thermo liquid to reach a stable height, place a
mark in this at 100°C
(4.65 x 3.56) x (10−1 x 102 ) 𝑚𝐿2
Multiply coefficients and add exponents
- Place 100 equally spaced divisions between 0 and 100
(16.55) x (101 )= 165.5 𝑚𝐿2
Change to scientific notion
- It is now calibrated using known values, can be used to
2
marks to represent 1°C
measure temp of objects between 0 and 100°C
𝑚𝐿2
1.655 x 10
__________
Unit Conversion, Error and Uncertainty
Accuracy
- How close an estimate is to a known standard
5
- ex. 140 can be written as 1.4 x 102 with two significant figures
in coefficient
- A number with left-end zeros, such as 0.000416 can be written
as 4.16 x 10−4 with three significant figures
Adding and Subtracting
- Sum or difference is determined by the smallest number of
Percent Uncertainty
- Ratio of uncertainty to the measured value, multiplied by one
significant figures to the right of the decimal point in any of the
original numbers
ex.
89.332+1.1= 90.432 round to 90.4
2.097-0.12= 1.977 round to 1.98
hundred
Multiplying and Dividing
ex.
The percent uncertainty associated with the measurement
(52.9 ± 0.5 mL) would be
Using estimate 52.9 mL, what would be the range of possible
values for the true volume?
- Number of significant figures in the final product or quotient is
equal to the number of significant figures in the starting value
that has the fewest significant figures
ex.
2.8 x 4.5039= 12.61092 round to 13
6.85 ÷ 112.04= 0.0611388789 round to 0.0611
0.2786 x 8= 2.229
(The value 8 is known to be exact so it has an infinite number of
significant figures)
Exact Quantities
Upper estimate= 52.9 + 0.5= 53.4 mL
Lower estimate= 52.9 - 0.5= 52.4 mL
Somewhere between these two values
- When numbers are known exactly, significant figure rules don’t
apply
- Happens when objects are counted rather than measured
Percent Error
- Expression of the accuracy of a measurement
- Possible sources of error
Calculating Density
- Expression of the mass of a substance in terms of volume
occupied by the substance
ex.
-Misreading a graduated cylinder. Error may be in the method or
procedure like not drying a wet solid before weighing.
-A pure solid may have residue fixed to it affecting its mass.
-Improper calibration
__________
Significant Figures
density= mass = m
volume v
- Reported in terms of gram per milliliter (g/mL) or the equivalent
value, grams per cubic centimeter (g/ 𝑐𝑚3 )
- Scientist compare the density of an object to the density of
water which is 1 g/mL at room temperature (25°C)
- Consist of all certain digits in that measurement plus one
uncertain or estimated digit
- Associated with uncertainty of a measurement
Material
hydrogen
oxygen
Density g/mL
0.00009
0.0014
water
1.0
aluminum
2.7
iron
7.9
gold
19.3
Mass
6
- Quantity of inertia possessed by an object
- Appropriate form
- Concept that matter is continuous, infinite, and comes in
Weight
- By Plato and Aristotle
- Refers to the gravitational force acting on a mass, as measured
on a scale
Determining the Volume of Regularly Shaped Objects
- To calculate density, know volume first
- To calculate volume:
Volume of cube
Of sphere
Of cylinder
every form all around us, and could be divided and
subdivided into smaller pieces without limit
• Discontinuous Theory of Matter
- Concept that matter is actually finite and not limitless
- Aristotle, great ‘authority’ taught against it
- Democritus proposed this
1. Everything is composed of atoms, physically indivisible
2. Atoms are indestructible and constantly in motion
3. There is empty
l x space
w x h between atoms
3
4/3 π𝑟
• Law of Definite Propositions
- Published in 1799
2
π𝑟 h
- States that chemical compounds always contain the
Of cone
Determining the Volume of Irregularly Shaped Objects
- We can determine volume by measuring the volume of water
2
same proportion
1/3 π𝑟of
h elements by mass no matter the
amount
- Elements combine In fixed ratios based on their mass
- Joseph Louis Proust (1754-1826)
displaced by the solid
ex.
Measure volume of toy dinosaur
Place it in water, the volume measured in the container increases
by an amount that’s equal to the volume of the toy
(works only to solids that don’t dissolve)
• Law of Conservation of Mass
- States that the mass f a reactant must be equal to the
mass of the product for any chemical process
Temperature Scales
• Fahrenheit- mostly used in US, defines normal freezing and
boiling point of water as 32 °F and 212°F
• Celsius- used by most countries, defines normal freezing and
boiling point of water as 0°C and 100°C
• Kelvin- or absolute temperature scale, defines absolute zero as
the lowest theoretically possible temp meaning that temps
expressed in Kelvin can’t be negative number
• Law of Multiple Proportions
- States that if two elements form more than one
compound between them, the the ratios of the masses of
the second element that combine with a fixed mass of
the first element will be ratios of small whole numbers
Conversion
__________
Evolution of Atomic Model
Atom
- fundamental, indivisible particles that make up matter
• Continuous Theory of Matter
- It quantified gaseous chemical species viewed as
missing matter that was not involved in chemical process
- Antoine Lavoisier
- John Dalton
• Atomic Theory
- Dalton, 1804
1. All matter is composed of extremely small particles, atom
2. Atoms of a given element are identical in size, mass and
other properties. Atoms of different elements differ in
size, mass and other properties.
3. Atoms can’t be subdivided, created or destroyed
4. Atoms of different elements can combine in simple whole
number ratios to form chemical compounds.
5. In chemical reactions, atoms are combined, separated or
rearranged.
(Modification)
1. Atom can be further sub-divided
2. Not all atoms of an element have identical massess
__________
Structure of an Atom
• Cathode Rays
- William Crookes, 1877
- How electrical current behaves in a vacuum tube
7
- In an experiment, he passed an electric current through
an evacuated phosphorous-coated glass cylinder with an
object in the center
- A shadow was cast by the object
- The phosphorous on the terminal end became
fluorescent except for the region behind object
- Electrical current was blocked by object
- Electrical current, cathode rays, was composed of
Electronic Structure of Atoms
Energy Levels (electron shells)
- Fixed distances from the nucleus of an atom where electrons
may be found
- You can stand on one step or another but not in between the
steps (same goes for electrons)
- They can occupy one energy level or another but no the space
between energy levels
streams of particles
Energy Level I (energy level K)
- Have the least amount of energy
- As you go farther from nucleus, electrons at higher levels have
more energy, and their energy increases by a fixed, discrete
amount
- J.J. Thompson interpreted that cathode rays must
consist of charged particles that have mass
- 1897, he referred to these as negatively charged
particles as corpuscles
-
Electrons can jump from a lower to a next higher level
They give off energy often in light form
Different atoms have different arrangements of electrons
Can hold a maximum of two electrons
Has only 1 orbital
- He revised the model to plum pudding model
- Atom was comprised of negatively charged
particles in a field of positive charge
Proton- positively charged particle that has a large mass
compared to electrons and can be found in the nucleus of the
atom
Neutron- uncharged particle with a mass nearly equal to proton
and can be found in the nucleus of the atom
- Electrons with most energy are found in Energy Level IV
Charge of Electron
• Electron- negatively charged particle that has small mass
compared to the mass of other subatomic particles
- In 1909, Robert Millikan and Harvey Fletcher devised the oil
drop experiment to determine the charge of a single electron
- Consisted of an apparatus in which small, charged oil
drops were passed through an electric field that was
created by two oppositely charged parallel metal plates
- The rate at which the oil drops fell was used to determine
the magnitude of the charge of an electron
- They calculated the charge of an electron to be 1.5924 x 10−9
coulomb (C)
- SI unit, where 1 coulomb= 1 ampere x 1 second
- Today the accepted value for charge of an electron is
- Millikan calculated the mass of an electron, and the accepted
value is 9.10938215 x 10
- Can hold maximum of 8
- Has 4 orbitals
Outermost Level
- Electrons here have a special significance
Orbital
- A volume of space within an atom where an electron is
most likely to be found
- Some orbitals are shaped like spheres (S orbitals) and
some are like dumbbells (P orbitals)
- Regardless of shape, each orbital can hold maximum of
2 electrons
- 3-dimensional region of space where there is a high
1.602176487 x 10−19
−31
Energy Level II (level L)
kg
Discovery of the X-ray
- Wilhem Conrad Roentgen studied behavior of electricity in
discharge tubes filled with gas which conduct an electric
current
General Chemistry
probability of finding an electron
Electrons
- Are tiny, negatively charged particles in atoms that move
around the positive nucleus at center
- Always added to the lowest energy level first until it has
the maximum number of electrons possible
- Then electrons are added to the next higher level until
level is full
8
Quantum Theory
Hydrogen Atoms
- Smallest atoms
- Have one electron orbiting the nucleus (this one electron
- Suggest that energy comes in discrete packages called quanta
(electromagnetic radiation, photons)
- Referred to as quantum mechanics that offers explanations for
is in the first energy level)
- Bigger atoms have more electrons
the behavior of electrons inside electron clouds
- It is impossible to simultaneously measure energy and position
of an electron
- Electron behavior is different than behavior of normal sized
particles
• Probability distribution map- orbital
Edward Schrodinger (1887-1961)
- In 1926, Australian physicist used a wave particle duality
of the electron to develop and solve complex
mathematical equation that described the behavior of the
electron in hydrogen atom
- When energy is well-defined but position is not
Schrodinger’s equation
Quantum Mechanical Model
- From the solution of Schrodinger where he used waveparticle duality of electron to develop and solve complex
mathematical equation
- Quantization of electron energies is a requirement in
order to solve equation
• Wave Function
- Gives only the probability of finding an electron at a given
point around nucleus
- Solutions to wave equation
• Electron cloud
- Location of electrons in the model
- Because of uncertainty principle, there’s no way of
knowing where the electron is
- Has variable densities: high and low
• Orbital- in here, it is customary to refer this region within
which there is 90% probability of finding an electron
(Shapes: s, p, d, f)
Valence Electrons
- Determine properties of an atom
- Electrons in the highest energy level available for
chemical bonding
- In covalent bond, valence electrons are available to be
shared with another atom to fill available energy levels
- Outermost level has 8 electrons, but when all 8 are
present, resulting chemical is an inert noble gas
- Atoms with less than 8 in outermost shells will bond with
other atoms to share enough electrons to make 8
How to determine valence electron
- For neutral atoms, number of valence electrons is equal to the
atom’s main group number
- The main group for an element can be found from its column
on the periodic table
- ex. Carbon is in group 4 and has 4 valence electrons. Oxygen
is in group 6 and has 6 valence electrons.
- The stable energy levels for an electron are those that have
integer values in 3 positions in the equation (n, l, m)
Quantum Numbers (four special numbers)
- (n, l, m) from Schrodinger and the 4th comes from an extension
of the theory
- n is a positive integer that indicates main energy level of an
electron
- These numbers describe energy of an electron
- Each electron has exactly 4 quantum numbers
- no 2 electrons have the same 4
• Principal Quantum Number
- Main shell in which the 𝑒− exists
- Determines the energy of 𝑒−
- Determines size of orbital
• Angular Momentum Quantum Number (l) (Magnetic)
- Describes general shape or region an electron occupies
- Describes orbital orientation
- Its value depends on the value of the principal quantum number
n
- Can have positive values of zero to (n-1)
• Azimuthal Quantum Number (ml) (Orbital or Angular)
-
Determines orbital shape in space
Gives sub shell in which the 𝑒− exists
Contributes the energy of 𝑒−
Electrons can be situated in one of three planes in 3
dimensional space around given nucleus (x, y, z)
- L can be (2l+1)
9
• Spin Quantum Number
- Orientation of rotation around itself
- Spin for a given electron
- An electron can have one of two associated spins, (+1,2) or (1/2)
- Cannot have zero spin
- Represented with arrows
- A single orbital can hold a maximum of 2 electrons and each
must have opposite spin
- The largest known atom contains slightly more than 100
electrons
- No more that 7 principal energy levels are needed to describe
all the electrons of known atoms
- Principal and sub-levels are in red, ones in black are
theoretically present but are never used for known atoms
Hund’s Rule and Orbital Filling Diagrams
- Orbitals of equal energy are each occupied by one electron
before any orbital is occupied by a second electron and that
each of the single electrons must have the same spin
Orbital Filling Diagram- visual way to represent the
arrangement of all electrons (square-orbitals,
arrowselectrons)
- An arrow upwards indicates one spin direction, downward
indicates other direction
Oxygen- It has four 2p. After each 2p orbital has one electron in
it, the fourth electron can be placed in the first 2p orbital with a
spin opposite that of the other electron in that orbital
Electron Configuration
- This notations eliminate boxes and arrows of orbital filling
diagrams
- Each occupied sub-level designation is written followed by a
superscript that is number of electrons in that sub-level
Pauli Exclusion Principle
- No two electrons can have the same set of four quantum
ex. For carbon
1. List known quantities and plan problem
2. Atomic number, z=6
3. Construct diagram
numbers
- The energy of the electron is specified by the principal, angular
momentum, and magnetic quantum numbers
- If those 3 numbers are identical for 2 electrons, the spin
numbers must be different
4. 1𝑠 2 2𝑠 2 2𝑝2
Anomalous Electronic Configuration
- Where certain elements don’t follow Aufbau principle
Aufbau Principle
- An electron occupies orbitals in order from lowest energy to
highest
- Can be used to describe locations and energy levels of every
electron in a given atom
10