Atomos: Not to Be Cut Chapter 5 Lesson 1. 2 Atomic Theory Atoms are building blocks of elements...
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Transcript of Atomos: Not to Be Cut Chapter 5 Lesson 1. 2 Atomic Theory Atoms are building blocks of elements...
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Atomic TheoryAtomic Theory
Atoms are building blocks of elements Atoms are building blocks of elements
Similar atoms in each elementSimilar atoms in each element
Different from atoms of other elementsDifferent from atoms of other elements
Two or more different atoms bond in simple Two or more different atoms bond in simple
ratios to form compoundsratios to form compounds
33
Subatomic ParticlesSubatomic Particles
ParticleParticle Symbol Symbol Charge Charge RelativeRelativeMassMass
ElectronElectron e e-- 1-1- 0 0
ProtonProton p p++ + + 1 1
NeutronNeutron n n 0 0 1 1
44
Location of Subatomic ParticlesLocation of Subatomic Particles
1010-13 -13 cmcm
electronselectrons
protonsprotons
neutronsneutrons
1010-8 -8 cmcm
nucleus
55
Atomic NumberAtomic Number
Counts the numberCounts the number
of of
protonsprotons
in an atomin an atom
66
Periodic TablePeriodic Table
Represents physical and chemical behavior Represents physical and chemical behavior
of elementsof elements
Arranges elements by increasing atomic Arranges elements by increasing atomic
numbernumber
Repeats similar properties in columns known Repeats similar properties in columns known
as chemical families or groupsas chemical families or groups
88
Atomic Number on the Periodic Atomic Number on the Periodic TableTable
1111
NaNa
Atomic Number
Symbol
99
All atoms of an element have All atoms of an element have the same number of protonsthe same number of protons
1111
NaNa
11 protons
Sodium
1010
Learning Check AT 1Learning Check AT 1
State the number of protons for atoms of each State the number of protons for atoms of each of the following:of the following:
A. Nitrogen A. Nitrogen
1) 5 protons1) 5 protons 2) 7 protons 3) 14 2) 7 protons 3) 14 protonsprotons
B. Sulfur B. Sulfur
1) 32 protons1) 32 protons 2) 16 protons 3) 6 protons 2) 16 protons 3) 6 protons
C. BariumC. Barium
1) 137 protons 2) 81 protons 3) 56 protons1) 137 protons 2) 81 protons 3) 56 protons
1111
Solution AT 1Solution AT 1
State the number of protons for atoms of each State the number of protons for atoms of each of the following:of the following:
A. Nitrogen A. Nitrogen
2) 7 protons 2) 7 protons
B. Sulfur B. Sulfur
2) 16 protons2) 16 protons
C. BariumC. Barium
3) 56 protons3) 56 protons
1212
Number of ElectronsNumber of Electrons
An atom is neutral An atom is neutral The net charge is zeroThe net charge is zero Number of protons = Number of electronsNumber of protons = Number of electrons Atomic number = Atomic number = Number of electronsNumber of electrons
1313
Mass NumberMass Number
Counts the number Counts the number
of of
protons protons and and neutronsneutrons
in an atomin an atom
1414
Atomic SymbolsAtomic Symbols
Show the Show the mass number and atomic numbermass number and atomic number
Give the symbol of the elementGive the symbol of the element
mass numbermass number
23 23 NaNa sodium-23sodium-23
atomic numberatomic number 1111
1515
More Atomic SymbolsMore Atomic Symbols
1616 3131 6565
OO P P Zn Zn
88 1515 3030
8 p8 p++ 15 p15 p++ 30 p30 p++
8 n8 n 16 n16 n 35 n35 n8 e8 e-- 1515 ee-- 30 e30 e--
1616
IsotopesIsotopes
Atoms with the same number of protons, Atoms with the same number of protons,
but different numbers of neutrons. but different numbers of neutrons.
Atoms of the same element (same atomic Atoms of the same element (same atomic
number) with different mass numbersnumber) with different mass numbers
Isotopes of chlorineIsotopes of chlorine
3535ClCl 3737ClCl1717 1717
chlorine - 35 chlorine - 37chlorine - 35 chlorine - 37
1717
Learning Check AT 2Learning Check AT 2
Naturally occurring carbon consists of three Naturally occurring carbon consists of three isotopes, isotopes, 1212C, C, 1313C, and C, and 1414C. State the number of C. State the number of protons, neutrons, and electrons in each of protons, neutrons, and electrons in each of these carbon atomsthese carbon atoms. .
1212CC 1313CC 1414CC 66 6 6 6 6
#P _______ _______ _______ #P _______ _______ _______
#N _______ _______ _______#N _______ _______ _______
#E _______ _______#E _______ _______
1818
Solution AT 2Solution AT 2
1212CC 1313CC 1414CC 66 6 6 6 6
#P #P __6_____6___ _ 6____ 6___ ___ ___66___ ___
#N __#N __66___ ____ _ __77___ ______ ___88___ ___
#E #E __6_____6___ _ 6____ 6___ ___ ___66___ ___
1919
Learning Check AT 3Learning Check AT 3An atom of zinc has a mass number of 65.An atom of zinc has a mass number of 65.
A.A. Number of protons in the zinc atomNumber of protons in the zinc atom
1) 301) 30 2) 352) 35 3) 653) 65
B.B. Number of neutrons in the zinc atomNumber of neutrons in the zinc atom
1) 301) 30 2) 352) 35 3) 653) 65
C. What is the mass number of a zinc isotope C. What is the mass number of a zinc isotope
with 37 neutrons?with 37 neutrons?
1) 371) 37 2) 652) 65 3) 673) 67
2020
Solution AT 3Solution AT 3
An atom of zinc has a mass number of 65.An atom of zinc has a mass number of 65.
A.A. Number of protons in the zinc atomNumber of protons in the zinc atom
1) 301) 30
B.B. Number of neutrons in the zinc atomNumber of neutrons in the zinc atom
2) 352) 35
C. What is the mass number of a zinc isotope C. What is the mass number of a zinc isotope
with 37 neutrons?with 37 neutrons?
3) 673) 67
2121
Learning Check AT 4Learning Check AT 4
Write the atomic symbols for atoms with the Write the atomic symbols for atoms with the following:following:
A. 8 pA. 8 p++, 8 n, 8 e, 8 n, 8 e-- ______________________
B.B. 17p17p++, 20n, 17e, 20n, 17e-- ______________________
C. 47pC. 47p++, 60 n, 47 e, 60 n, 47 e-- ______________________
2222
Solution AT 4Solution AT 4
1616OOA. 8 pA. 8 p++, 8 n, 8 e, 8 n, 8 e-- 88
B.B. 17p17p++, 20n, 17e, 20n, 17e-- 3737ClCl 1717
C. 47pC. 47p++, 60 n, 47 e, 60 n, 47 e-- 107107AgAg 4747
2323
Learning Check AT 5Learning Check AT 5
An atom has 14 protons and 20 neutrons.An atom has 14 protons and 20 neutrons.A.A. Its atomic number isIts atomic number is
1) 141) 14 2) 162) 16 3) 343) 34
B. Its mass number isB. Its mass number is1) 141) 14 2) 162) 16 3) 343) 34
C. The element isC. The element is1) Si1) Si 2) Ca2) Ca 3) Se3) Se
D.D. Another isotope of this element isAnother isotope of this element is
1)1) 3434X X 2)2) 3434X X 3)3) 3636XX 16 16 14 14 14 14
2424
Solution AT 5Solution AT 5
An atom has 14 protons and 20 neutrons.An atom has 14 protons and 20 neutrons.A.A. It has atomic numberIt has atomic number
1) 141) 14
B. It has a mass number ofB. It has a mass number of3) 343) 34
C. The element isC. The element is1) Si1) Si
D.D. Another isotope of this element would beAnother isotope of this element would be
3) 3) 3636XX 1414
2525
Masses of AtomsMasses of Atoms A scale designed for atoms gives their small A scale designed for atoms gives their small
atomic masses in atomic mass units (amu)atomic masses in atomic mass units (amu)
An atom of An atom of 1212C was assigned an exact mass of C was assigned an exact mass of
12.00 amu12.00 amu
Relative masses of all other atoms was Relative masses of all other atoms was
determined by comparing each to the mass of determined by comparing each to the mass of 1212C C
An atom twice as heavy has a mass of 24.00 An atom twice as heavy has a mass of 24.00
amu. An atom half as heavy is 6.00 amu.amu. An atom half as heavy is 6.00 amu.
2626
Atomic MassAtomic Mass
Listed on the periodic tableListed on the periodic table
Gives the mass of “average” atom of each Gives the mass of “average” atom of each
element compared to element compared to 1212C C
Average atom based on all the isotopes and their Average atom based on all the isotopes and their
abundance %abundance %
Atomic mass is not a whole numberAtomic mass is not a whole number
Na22.99
2727
Learning Check AT6Learning Check AT6
Using the periodic table, specify the atomic Using the periodic table, specify the atomic mass of each element (round to the tenths mass of each element (round to the tenths place): place):
A.A. calciumcalcium ____________________
B. aluminumB. aluminum ____________________
C. C. leadlead ____________________
D. bariumD. barium ____________________
E. ironE. iron ____________________
2828
Solution AT6Solution AT6
Using the periodic table, specify the atomic Using the periodic table, specify the atomic mass of each element (round to the tenths mass of each element (round to the tenths place):place):
A.A. calciumcalcium _40.1 amu _ _40.1 amu _
B. aluminumB. aluminum _27.0 amu __27.0 amu _
C. C. leadlead __207.2 amu207.2 amu__
D. bariumD. barium _137.3 amu__137.3 amu_
E. ironE. iron _55.8 amu___55.8 amu__
2929
Calculating Atomic MassCalculating Atomic Mass
Percent(%) abundance of isotopesPercent(%) abundance of isotopes
Mass of each isotope of that elementMass of each isotope of that element
Weighted average =Weighted average =
mass isotopemass isotope11(%)(%) + + mass isotopemass isotope22(%)(%) + … + …
100100 100100
3030
Atomic Mass of MagnesiumAtomic Mass of Magnesium
Isotopes Isotopes Mass of Isotope AbundanceMass of Isotope Abundance 2424Mg Mg == 24.0 amu 24.0 amu 78.70%78.70%
2525Mg Mg = = 25.0 amu 25.0 amu 10.13%10.13%
2626Mg Mg = = 26.0 amu26.0 amu 11.17%11.17%
Atomic mass (average mass) Mg = 24.3 amuAtomic mass (average mass) Mg = 24.3 amu
Mg24.3
3131
Learning Check AT7Learning Check AT7
Gallium is a metallic element found in Gallium is a metallic element found in
small lasers used in compact disc players. small lasers used in compact disc players.
In a sample of gallium, there is 60.2% of In a sample of gallium, there is 60.2% of
gallium-69 (68.9 amu) atoms and 39.8% of gallium-69 (68.9 amu) atoms and 39.8% of
gallium-71 (70.9 amu) atoms. What is the gallium-71 (70.9 amu) atoms. What is the
atomic mass of galliumatomic mass of gallium??
3232
Solution AT7Solution AT7
Ga-69 Ga-69
68.9 amu x 68.9 amu x 60.2 60.2 = = 41.5 amu for 41.5 amu for 6969GaGa
100100
Ga-71 (%/100)Ga-71 (%/100)
70.9 amu x 70.9 amu x 39.8 39.8 = = 28.2 amu for 28.2 amu for 7171GaGa
100100
Atomic mass Ga Atomic mass Ga = = 69.7 amu69.7 amu
3333
Finding An Isotopic MassFinding An Isotopic Mass
A sample of boron consists of A sample of boron consists of 1010B (mass B (mass 10.0 amu) and 10.0 amu) and 1111B (mass 11.0 amu). If B (mass 11.0 amu). If the average atomic mass of B is 10.8 the average atomic mass of B is 10.8 amu, what is the % abundance of each amu, what is the % abundance of each boron isotope?boron isotope?
3434
Assign X and Y values:Assign X and Y values:X = % X = % 1010B Y = % B Y = % 1111B B
Determine Y in terms of XDetermine Y in terms of XX + Y = 100X + Y = 100Y = 100 - XY = 100 - X
Solve for X:Solve for X:X (10.0)X (10.0) + + (100 - X )(11.0) (100 - X )(11.0) = 10.8 = 10.8
100 100100 100
Multiply through by 100Multiply through by 10010.0 X + 1100 - 11.0X = 108010.0 X + 1100 - 11.0X = 1080