The Amazing AtomThe Amazing Atom
AtomsAtoms
All matter is made of very tiny All matter is made of very tiny particlesparticlesThese These atomsatoms have the same have the same
properties as larger particles ofproperties as larger particles of
the matter havethe matter have
Parts of the AtomParts of the Atom
Subatomic ParticlesSubatomic Particles – smaller – smaller than an atom (parts)than an atom (parts)
ProtonProtonNeutronNeutronElectronElectron
Subatomic ParticlesSubatomic Particles
Protons (pProtons (p++))Positive chargePositive chargeEach one has a charge of +1Each one has a charge of +1Located in the nucleusLocated in the nucleusEach one has a mass of 1amu Each one has a mass of 1amu (atomic mass unit)(atomic mass unit)
Subatomic ParticlesSubatomic Particles
Neutrons (nNeutrons (n00))No chargeNo chargeLocated in the nucleusLocated in the nucleusEach one has a mass of 1amu Each one has a mass of 1amu (atomic mass unit)(atomic mass unit)
Subatomic ParticlesSubatomic Particles
Electrons (eElectrons (e--))Negative chargeNegative chargeEach one has a charge of -1Each one has a charge of -1Located in the space (cloud) Located in the space (cloud) around the nucleusaround the nucleus
Each one has a mass of about Each one has a mass of about 0.0006amu (atomic mass unit)0.0006amu (atomic mass unit)
The AtomThe Atom
The The nucleusnucleus has p has p++ and n and n00
Positively chargedPositively chargedThe The electron cloudelectron cloud has e has e--
Negatively chargedNegatively chargedThe number of protons equals the The number of protons equals the
number of electrons number of electrons in a neutral in a neutral atomatom
Periodic TablePeriodic Table
The periodic table gives us lots of The periodic table gives us lots of information about the elements.information about the elements.
1
H
Hydrogen
1.008
Atomic Number
Element Symbol
Element Name
Average Atomic Mass
Symbol PracticeSymbol Practice
For the element name, give the For the element name, give the symbol.symbol.
HeliumHelium
CarbonCarbon
SulfurSulfur
OxygenOxygen
MagnesiumMagnesium
Element PracticeElement Practice
For the symbol, give the element For the symbol, give the element name.name.
LiLi
NN
ArAr
AlAl
NaNa
Atomic NumberAtomic Number
Atoms of different elements are Atoms of different elements are differentdifferent
The number of protons in the nucleus The number of protons in the nucleus is the is the atomic numberatomic number of an element of an element
Atomic NumberAtomic Number
The The atomic numberatomic number identifies the identifies the elementelement
Like DNA Like DNA
for an elementfor an element
Proton PracticeProton Practice
Practice: How many protons are in Practice: How many protons are in each of the following elements?each of the following elements?
CarbonCarbon
Potassium Potassium
NitrogenNitrogen
Calcium Calcium
SiliconSilicon
ElectronsElectrons
Electrons give atoms their chemical Electrons give atoms their chemical propertiesproperties
In order for an atom to have a In order for an atom to have a neutral neutral chargecharge, it must have the same , it must have the same number of electrons as it has protons.number of electrons as it has protons.
Electrons = protons = atomic numberElectrons = protons = atomic number
Electron PracticeElectron Practice
Practice: How many electrons are in Practice: How many electrons are in each of the following elements?each of the following elements?
HeliumHelium
Chlorine Chlorine
NitrogenNitrogen
Aluminum Aluminum
BoronBoron
Mass NumberMass Number
All atoms have a All atoms have a mass numbermass numberWe can figure it out by rounding the We can figure it out by rounding the
Average Atomic Mass to the nearest Average Atomic Mass to the nearest whole numberwhole number
Mass number = protons + neutronsMass number = protons + neutronsNeutrons = Mass number – protonsNeutrons = Mass number – protons
Finding NeutronsFinding NeutronsExample: CarbonExample: CarbonRound the Average Atomic Mass to Round the Average Atomic Mass to
the nearest whole number: the nearest whole number:
12.01 rounds to 1212.01 rounds to 12How many protons in carbon?How many protons in carbon?
66Neutrons = Mass number – protonsNeutrons = Mass number – protons
Neutrons = 12 – 6 = 6Neutrons = 12 – 6 = 6
Neutron PracticeNeutron Practice
Practice: How many neutrons are in Practice: How many neutrons are in each of the following elements?each of the following elements?
OxygenOxygen
Chlorine Chlorine
ArgonArgon
Aluminum Aluminum
PhosphorusPhosphorus
Atomic Structure PracticeAtomic Structure PracticeFirst 25 Elements ActivityFirst 25 Elements Activity
IsotopesIsotopes
IsotopesIsotopes of an element have the of an element have the same number of protons, but different same number of protons, but different numbers of neutrons.numbers of neutrons.
There can be many isotopes of the There can be many isotopes of the same element.same element.
Atom Concept MapAtom Concept Map
IsotopesIsotopes
The The average atomic massaverage atomic mass of an of an element is determined by taking a element is determined by taking a weighted average of all of the weighted average of all of the isotopes of an element.isotopes of an element.
Isotope SymbolsIsotope SymbolsIsotopes of Isotopes of
elements have elements have symbols called symbols called isotopic symbols:isotopic symbols:
X = Element symbolX = Element symbol
A = Mass numberA = Mass number
Z = Atomic numberZ = Atomic number
XAZ
Isotope SymbolsIsotope Symbols
The isotope symbol for The isotope symbol for carbon would be:carbon would be:X = Element symbol = CX = Element symbol = C
A = Mass number = 12A = Mass number = 12
Z = Atomic number = 6Z = Atomic number = 6
C126
Isotopes of Candium ActivityIsotopes of Candium Activity
Quick CheckQuick Check
What is the atomic number of antimony?What is the atomic number of antimony?What is the symbol for tungsten?What is the symbol for tungsten?How many protons are in tin?How many protons are in tin?How many electrons are in potassium?How many electrons are in potassium?How many neutrons are in phosphorus?How many neutrons are in phosphorus?What is the mass number of lead?What is the mass number of lead?
Isotopic Symbol PracticeIsotopic Symbol Practice
The Bohr Model of the AtomThe Bohr Model of the Atom
BohrBohr developed the developed the “planetary”“planetary” model model of the atom, with electrons in orbits of the atom, with electrons in orbits around the nucleus.around the nucleus.
Each of these “orbits”, which we now Each of these “orbits”, which we now call call shellsshells, is an energy level for , is an energy level for electrons.electrons.
We start by filling the shell closest to We start by filling the shell closest to the nucleus firstthe nucleus first
The Bohr Model of the AtomThe Bohr Model of the Atom
Each of the shells can only hold a Each of the shells can only hold a certain numbercertain number of electrons of electrons11stst shell – maximum 2 electrons shell – maximum 2 electrons22ndnd shell – maximum 8 electrons shell – maximum 8 electrons33rdrd shell – maximum 18 electrons shell – maximum 18 electronsAdditional shells can hold more, but Additional shells can hold more, but
we do not have to go past the 3we do not have to go past the 3rdrd shellshell
The Bohr Model of the AtomThe Bohr Model of the Atom
Let’s see what that looks like for hydrogen:Let’s see what that looks like for hydrogen:
How many protons? How many electrons?How many protons? How many electrons?How many neutrons?How many neutrons?
The Bohr Model of the AtomThe Bohr Model of the Atom
Let’s see what that looks like for lithium:Let’s see what that looks like for lithium:
Build a Bohr DiagramBuild a Bohr Diagram
Bohr Model PracticeBohr Model Practice
Please do only the following elements Please do only the following elements on your Bohr Model Worksheet:on your Bohr Model Worksheet:
SodiumSodium HydrogenHydrogen
CarbonCarbon SiliconSilicon
OxygenOxygen ChlorineChlorine
ArgonArgon MagnesiumMagnesium
Human Bohr ModelHuman Bohr Model
Human Bohr Model.aviHuman Bohr Model.avi