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Transcript
1
Name: ________________________
Student Number: _____________________
Chemistry 1000 Final Exam
Version A
Fall 2012
1)
2)
3)
4)
5)
6)
7)
8)
INSTRUCTIONS
Read the exam carefully before beginning. There are 21 questions on pages 2 to 14 followed
by 2 pages of “Data Sheet” (including periodic table) and a blank page for any rough work.
Please ensure that you have a complete exam. If not, let an invigilator know
immediately. All pages must be submitted at the end of the exam.
If your work is not legible, it will be given a mark of zero.
Marks will be deducted for incorrect information added to an otherwise correct answer.
You may use a calculator.
Show your work for all calculations. Answers without supporting calculations will not be
given full credit.
Marks will be deducted for improper use of significant figures and for numerical answers
with incorrect/missing units.
Do not open the exam until you are told to begin. Beginning prematurely will result in
removal of your exam paper and a mark of 0.
You have 3 hours to complete this exam. Nobody may leave the exam room during the first
hour or the last 15 minutes of the exam.
Q
Mark
Q
Mark
1
/4
11
/9
2
/6
12
/ 12
3
/ 12
13
/ 10
4
/4
14
/7
5
/4
15
/ 18
6
/5
16
/2
7
/ 10
17
/3
8
/2
18
/5
9
/5
19
/3
10
/3
20
/7
21
/1
Total
/ 132
2
Name: ________________________
1.
Student Number: _____________________
Complete the table below.
[4 marks]
Name
Formula
copper(II) hydroxide
Cu (OH )2
phosphate ion
PO43−
24
12
magnesium-24 ion
nitric acid
2.
(a)
HNO3
Write balanced chemical equations for each of the following processes:
133
Ba decays by electron capture
133
56
Ba + 0−1 e →133
55 Cs
(b)
Nitrogen reacts with magnesium
N 2 ( g ) + 3Mg ( s ) → Mg 3 N 2 ( s )
(c)
Potassium reacts with water
2 K ( s ) + 2 H 2 O(l ) → 2 KOH ( aq ) + H 2 ( g )
or
2 K ( s ) + 2 H 2 O(l ) → 2 K (+aq ) + 2OH (−aq ) + H 2 ( g )
(d)
Calcium reacts with bromine
Ca ( s ) + Br2 (l ) → CaBr2 ( s )
(e)
Aqueous sodium chloride is subjected to electrolysis
2 NaCl ( aq ) + 2 H 2 O(l ) → 2 NaOH ( aq ) + H 2 ( g ) + Cl 2 ( g )
or
2Cl (−aq ) + 2 H 2 O(l ) → 2OH (−aq ) + H 2 ( g ) + Cl 2 ( g )
(f)
Aluminium oxide is reacted with aqueous sodium hydroxide.
Al 2 O3( s ) + 2 NaOH ( aq ) + 3H 2 O( l ) → 2 Na[Al (OH )4 ]( aq )
or
Mg 2 +
Al 2 O3( s ) + 2OH (−aq ) + 3H 2 O(l ) → 2[Al (OH )4 ]( aq )
−
[6 marks]
3
Name: ________________________
3.
Student Number: _____________________
(a)
Chlorine, bromine and iodine are all capable of forming several different oxoanions.
On the other hand, fluorine can only form one oxoanion, and it is not stable.
[12 marks]
Draw the Lewis structure of the one oxoanion containing fluorine.
[1 mark]
(b)
[10 marks]
Complete the table below for any two of the four oxoanions of iodine.
Name of Molecular
Oxidation
Formula
Lewis structure*
Geometry
State of I
Name
linear
+1
hypoiodite
bent
+3
iodite
trigonal pyramidal
+5
iodate
tetrahedral
+7
periodate
(c)
Explain why fluorine behaves differently from the other halogens (in this context).[1 mark]
F is the most electronegative element on the periodic table and is in period 2. In any other
oxoanion of F, it would be necessary to have a positive formal charge on F (which is
forbidden) or for F to have more electrons than a complete octet (also forbidden).
4.
(a)
Lithium-6 and lithium-7 are the only two stable isotopes of lithium.
[4 marks]
Predict the likely modes of decay for isotopes of lithium that are heavier than the stable
isotopes. Briefly explain your reasoning. β– decay
[2 marks]
Heavier isotopes of an element have more neutrons than the stable isotopes so they will
decay in ways that lower N/Z. When a neutron decays to a proton, a β– particle is released.
Predict the likely modes of decay for isotopes of lithium that are lighter than the stable
isotopes. Briefly explain your reasoning. β+ decay or electron capture
[2 marks]
Lighter isotopes of an element have fewer neutrons than the stable isotopes so they will
decay in ways that raise N/Z. Electron capture converts a proton to a neutron. Positron
(β+) emission has the same effect.
(b)
4
Name: ________________________
5.
(a)
(b)
6.
Student Number: _____________________
For each pair of species, list the intermolecular force(s) which can act between the two
species. Also, circle the strongest intermolecular force acting between those two species.
[4 marks]
–
I (ion) and chloromethane (polar molecule) (see structure below)
ion-dipole
ion-induced dipole
dipole-induced dipole
induced dipole-induced dipole (aka London dispersion forces)
H2O (polar molecule) and NH3 (polar molecule)
hydrogen bonding
dipole-dipole
dipole-induced dipole
induced dipole-induced dipole (aka London dispersion forces)
Briefly describe a general chromatography experiment. Your description should identify
the main components of chromatography as well as explain how the technique is used to
separate compounds.
[5 marks]
A chromatography experiment separates compounds based on their relative affinity for two
different species:
• a stationary phase (bound to a column, packed in a column, etc.)
• a mobile phase (travels through a column or similar)
This affinity is usually determined by the strength of intermolecular forces.
Compounds with a stronger affinity for the stationary phase spend more time adsorbed to it
and therefore take longer to travel through the column.
Compounds with less affinity for the stationary phase (i.e. more affinity for the mobile
phase, relatively speaking) spend less time adsorbed to the stationary phase and travel
through the column faster.
5
Name: ________________________
Student Number: _____________________
7.
Define each term and give an example of each (a compound or a specific balanced reaction,
as appropriate).
[10 marks]
For (a) and (b), several good examples have been listed. A Lewis structure in addition to
(or instead of) the formula was appreciated.
(a)
Lewis acid
an electron pair acceptor
e.g.
BF3, CO2, SO3, Fe3+, Cu2+, H+
(b)
Brønsted base
a proton (H+) acceptor
e.g.
NH3, OH–, O2–, S2–, CO32–
(c)
Hydrogen bonding
a strong directional intermolecular force in which a lone pair on an atom of N, O or F is
partially donated to an atom of H that is bonded to another atom of N, O or F
e.g.
(d)
Ionization energy
the energy required to remove an electron from a neutral atom in the gas phase
e.g.
(e)
Enthalpy of electronic attraction (ΔEAH)
the energy released when an electron is added to a neutral atom in the gas phase
e.g.
6
Name: ________________________
8.
9.
(a)
Student Number: _____________________
Choose an element from group 14, group 15 or group 16 that has more than one allotrope.
Give two different allotropes that this element can form. You can use either molecular
formulae or names.
[2 marks]
Possible answers
carbon: diamond, graphite, graphene, fullerenes, nanotubes, etc.
phosphorus: P4 (white phosphorus), red phosphorus, black phosphorus
oxygen: O2, O3 (ozone)
sulfur: S8, plastic sulfur, S2, S3, S4, S5, S6, S7, etc.
[5 marks]
Draw the Lewis structures of carbon monoxide and carbon dioxide.
Include any nonzero formal charges on the appropriate atoms.
[2 marks]
(b)
What is unusual about the structure of carbon monoxide?
[1 mark]
It has a negative formal charge on carbon (not a very electronegative element) and a
positive formal charge on oxygen (one of the more electronegative elements).
(c)
Is carbon dioxide a Lewis acid or a Lewis base?
Lewis acid (primarily)
(d)
Is carbon monoxide a Lewis acid or a Lewis base?
[1 mark]
Lewis base
no credit for cutesy answers like “yes”
[1 mark]
no credit for cutesy answers like “yes”
10. Borane (BH3) does not exist in nature. Rather, it exists as diborane.
(a) Draw the Lewis structure of diborane.
[3 marks]
[1 mark]
(b)
What is unusual about this structure?
[1 mark]
It has three-center two-electron bonds (i.e. bonds in which the pair of electrons are shared
between three atoms instead of the usual two).
This is shown more clearly in the structure on the left.
(c)
Why do you think that diborane exists while borane does not?
[1 mark]
The boron atoms obey the octet rule in diborane but they do not in borane (BH3).
7
Name: ________________________
11.
(a)
(b)
Student Number: _____________________
Draw a full set of 3d orbitals.
Each orbital must be drawn on a properly labeled set of axes
[9 marks]
[5 marks]
In an octahedral complex, these orbitals split into two sets of different energies. Indicate
which orbitals belong to the higher-energy set and which to the lower-energy set. Explain
your choices.
[4 marks]
The higher-energy set is
The lower energy set is
and
,
and
.
.
In an octahedral complex, a metal is surrounded by six atoms, each donating an electron
pair to the metal. The six atoms are located along the three axes:
There is repulsion between the electron pairs donated by these atoms and the electrons in
the d orbitals of the metal, raising the energy of these d orbitals. This effect is stronger for
the two d orbitals pointing directly at the electron-donating atoms (i.e.
and
).
8
Name: ________________________
12.
(a)
Student Number: _____________________
[12 marks]
Draw an orbital energy diagram for the valence shell (both occupied and unoccupied
orbitals) of a beryllium atom.
[2 marks]
E
(b)
or
Give one possible complete set of quantum numbers for an electron in the highest energy
occupied orbital of beryllium.
[2 marks]
n = 2, l = 0, ml = 0, ms = +½
n = 2, l = 0, ml = 0, ms = -½
(c)
Explain why we can’t measure an enthalpy of electronic attraction for beryllium. [3 marks]
The next electron added to Be would start a new subshell (2p). The four electrons already
in Be would shield enough of the +4 nuclear charge (from the four protons in the nucleus)
that the new electrons would feel as much repulsion from the four electrons as it would feel
attraction to the nucleus. Thus, Be– would not form.
(d)
What is an emission spectrum?
[1 mark]
An emission spectrum shows the wavelengths of light emitted when excited state atoms
relax to the ground state.
(e)
The lowest energy transition in the emission spectrum of a beryllium atom has a
wavelength of 455 nm. To what transition does this line correspond?
[1 mark]
(f)
Calculate the energy difference between the two energy levels involved in the transition
described in part (e).
[3 marks]
The energy difference between the two energy levels is equal to the energy of the photon emitted
For light,
Therefore
9
Name: ________________________
Student Number: _____________________
13. Natural nitrogen samples from different sources have different molar masses. Two
particular samples of nitrogen have molar masses of 14.00648 g/mol and 14.00711 g/mol
respectively.
[10 marks]
(a)
Based on the molar masses given above, what is likely to be the most common isotope of
nitrogen?
[1 mark]
14
N (nitrogen-14)
(b)
How many protons and how many neutrons would the nucleus contain for the isotope you
named in part (a)?
[2 marks]
7 protons and 7 neutrons
(c)
What experimental method could we use to determine the molar mass? Explain briefly
what data we get from this experiment and how a molar mass is calculated from that data.
[4 marks]
We could use mass spectrometry (MS). This would give the exact mass of each isotope
present in the sample and the relative amount of each isotope present in the sample (wchich
allows calculation of percent abundance for each isotope). From this information, we use
the formula below to calculate molar mass:
%n
Mn
M av = ∑
100%
where n represents each isotope (%n is its percent abundance and Mn is its exact mass)
(d)
For the two samples described above and the experiment you described in part (c), what
data would be the same (within experimental error) and what data would be different? Can
you say (at least qualitatively) how they would differ? In other words, what data would be
larger/smaller for what sample?
[3 marks]
The exact mass of each isotope (Mn) is the same.
The relative amounts of each isotope will differ, so the percent abundances (%n) will differ.
The heavier sample (14.00711 g/mol) will contain a higher percentage of heavier isotopes
in comparison to the lighter sample.
10
Name: ________________________
14.
(a)
Student Number: _____________________
In proton therapy, a beam of protons is used to destroy tumors inaccessible to normal
surgical procedures. Ions (alpha particles, protons, etc.) progressively slow down as they
pass through biological tissues, and they do most of their damage just as they are about to
stop. By choosing their energy correctly, it is therefore possible to target a tumor at a very
specific depth, causing much less damage to intervening tissues. In one particular
operation, protons with a kinetic energy of 3.0×10-11 J per proton were used.
[7 marks]
Calculate the wavelength of these protons.
[3 marks]
Since protons are particles with mass,
E kinetic = 12 mv 2
v=
2 E kinetic
=
m
(
)
kg ⋅ m 2
1 2
2 3.0 ×10 −11 J
1u
×
× s
− 27
(1.007277u ) 1.660539 ×10 kg 1J
= 1.9 ×10 8
m
s
Then use the de Broglie equation to calculate wavelength
(
−34
)
kg ⋅ m 2
1 s2
6.626070 ×10 HzJ
h
1u
=
×
×
= 2.1×10 −15 m
λ=
mv (1.007277u ) 1.9 ×10 8 ms 1.660539 ×10 − 27 kg
1J
(
)
These protons are traveling at high enough speeds that (if we knew how), we would use
relativity theory to answer this problem. As it turns out, the answer is approximately the
same using classical physics (as done in the solution above) or using relativity.
(b)
At the stage at which tumors are noticed and treated, they typically have dimensions on the
order of centimeters. How does the wavelength of the protons compare? What, if anything,
would this imply for their use in proton therapy?
[2 marks]
The wavelength of the proton is substantially smaller than the dimensions of the tumour
(~1013 times smaller) so the protons can be used to precisely target the tumor.
(c)
A radiotherapist plans to deliver a proton therapy dose of 3.5 Gy to a tumor with an
estimated mass of 32 g.
(i) How much energy would this dose represent?
[1 mark]
1 Gy = 1 J/kg (absorbed dose)
1kg
= 0.11J
E = 3.5 kgJ × 32 g ×
1000 g
(ii)
How many protons would be needed to deliver this dose?
Each proton has a kinetic energy of 3.0×10-11 J
E
0.11J
# protons = total =
= 3.7 ×10 9 protons
J
E proton 3.0 ×10 −11 proton
[1 mark]
11
Name: ________________________
Student Number: _____________________
15.
In power plants, the burning of coal produces SO2 because the coal contains a small
amount of sulfur (hence sulfur is also burned). One way to remove SO2 from the flue gases
of power plants is to react it with an aqueous solution of H2S. One product of this reaction
is sulfur and the other is water.
[18 marks]
3
(a) How many moles of SO2 will be produced by burning 1.00 ton (1.00 ×10 kg) of coal
containing 3.00% sulfur by mass?
[3 marks]
Step 1: Calculate the mass of sulfur (S8) that will be burned
(
)
 3.00% 
3
m S8 = 
 1.00 ×10 kg = 30.0kg
 100% 
Step 2: Calculate the moles of sulfur that will be burned (molar mass of S8 is 256.528 g/mol)
1000 g
1mol
n S8 = 30.0kg ×
×
= 117mol
1kg
256.528 g
Step 3: Calculate the moles of SO2 that will be produced (every 1 mole of S8 contains 8 sulfur
atoms so will produce 8 moles SO2)
8molSO2
n SO2 = 117molS 8 ×
= 936molSO2
1molS 8
Note that you should get the same answer for moles of SO2 using any allotrope of sulfur (or even
a generic “S”). The only part that will give a different answer for each allotrope is step 2.
(b)
Write a balanced chemical equation for the reaction between SO2 and H2S.
16 H 2 S + 8SO2 → 3S 8 + 16 H 2 O
[1 mark]
(c)
What are the oxidation states of sulfur in SO2 and H2S?
[2 marks]
S in SO2: ____+4____
S in H2S: ____-2____
At 25 ˚C (298K) and 100 kPa, how many liters of hydrogen sulfide (H2S) gas would be
needed to remove all the SO2 formed in (a)?
[3 marks]
Step 1: Calculate the moles of H2S(g) required
16molH 2 S
n H 2 S = 936molSO 2 ×
= 1.87 ×10 3 molH 2 S
8molSO 2
(d)
Step 2: Calculate the volume of H2S(g) required
PV = nRT
(
)(
)
3
(298.15K ) 1kPa
nRT 1.87 ×10 mol 8.314462 mmol⋅ Pa
⋅K
V=
=
×
= 46.4m 3
(100kPa )
P
1000 Pa
3
This volume could be converted into L if you like. That would give 4.64×104 L.
12
Name: ________________________
Student Number: _____________________
15.
(e)
continued…
If the untreated flue gases of power plants are released into the environment, SO2 will react
with another pollutant, NO2, to produce sulfur trioxide and nitrogen monoxide. Draw a
formal charge-minimized Lewis structure for SO3.
[2 marks]
(f)
Fill in the following table for SO3.
[4 marks]
Name of Molecular
Geometry
Bond Angles
Average S-O Bond Order
Molecular Polarity?
(circle one)
trigonal planar
120°
2
polar / nonpolar
(g)
When SO3 dissolves in atmospheric water, we get acid rain! Write a balanced chemical
equation for the reaction of SO3 with water.
[1 mark]
(h)
In the Lewis acid-base reaction described in part (g), is SO3 acting as a Lewis acid or a
Lewis base? Support your answer with a reaction showing the movement of electrons
using curly arrows.
[2 marks]
Lewis acid
16.
(a)
[2 marks]
On what quantum number(s) does the orbital energy in a hydrogen atom depend? [1 mark]
n
Because there is only one electron in hydrogen, n is the only quantum number that affects
the energy of the electron.
(b)
Would your answer be the same for helium? If not, state the quantum number(s) on which
the energy of an orbital in a helium atom depends.
[1 mark]
n and l
Helium has more than one electron, so both n and l affect the energy of the orbitals.
(e.g. Electrons in 2s and 2p orbitals have different energies in a multi-electron atom.)
13
Name: ________________________
Student Number: _____________________
17. The Haber-Bosch process is arguably one of the most important industrial reactions.
[3 marks]
(a)
Write a balanced chemical equation for the reaction involved in the Haber-Bosch process.
Include all states of matter.
[2 marks]
(b)
What property of nitrogen makes this reaction so challenging?
Nitrogen is very unreactive due to the strong N≡N triple bond.
[1 mark]
[5 marks]
18. Consider the following complex: [Co(OH)6]4–
(a) What is the co-ordination number of cobalt in this complex?
[1 mark]
6
(b) What is the oxidation state of cobalt in this complex?
[1 mark]
–
+2
six OH ligands; overall charge of -4 so Co must be +2
(c) How many d electrons does cobalt have in this complex?
[1 mark]
2+
7
7
Co electron configuration is [Ar] 3d
(d) Would you expect this complex to absorb light with a longer or shorter wavelength than
[Co(NH3)6]2+? Explain.
[2 marks]
longer wavelength (i.e. lower energy light)
NH3 is a stronger field ligand than OH–. (see spectrochemical series on data sheet)
As such, the energy difference between the two sets of 3d orbitals is larger in [Co(NH3)6]2+.
Thus, [Co(NH3)6]2+ will absorb higher energy light and [Co(OH)6]4– will absorb lower
energy light.
Lower energy light has a longer wavelength.
19.
(a) Draw both isomers of [Fe(H2O)3(OH)3].
Your pictures must clearly show the correct geometry at Fe.
(b)
Clearly label your answers to part (a) as the fac isomer and the mer isomer.
[3 marks]
[2 marks]
[1 mark]
14
Name: ________________________
20.
(a)
(b)
Student Number: _____________________
The ground-state electron configuration of tantalum (Ta) is [Xe] 6s2 4f14 5d3.
[7 marks]
The most common oxidation states of tantalum are III, IV and V (i.e. +3, +4 and +5).
Write the ground-state electron configuration for each of the following ions:
[3 marks]
3+
14
2
Ta
[Xe] 4f 5d
Ta4+
[Xe] 4f14 5d1
Ta5+
[Xe] 4f14
Which of these ions would you expect to yield coloured complexes? Explain briefly.
Ta3+ and Ta4+
[4 marks]
For us to observe colour, the metal in a complex must have a partially filled d subshell so
that there are electrons in the lower-energy d orbitals and at least one vacancy in the
higher-energy d-orbitals. This is necessary for visible light to be absorbed and excite one
electron from a lower-energy to a higher-energy d orbital. When this absorption occurs, we
observe the complex as a combination of the colours of light not absorbed by the complex.
BONUS: In a special chelating solvent called diglyme, the following reaction can be performed
Here, the subscript (sol) indicates a species dissolved in diglyme (the solvent).
What is the oxidation state of the tantalum atom in the product complex?
[1 mark]
-1
that’s correct! a metal with a negative oxidation state! odd…
What would the corresponding ground-state electron configuration be?
[1 mark]
1
14
5
2
[Xe] 6s 4f 5d
would probably be lower energy than [Xe] 6s 4f14 5d4
(similar to electron configuration of Cr: [Ar]4s1 3d5)
21.
What was the most useful and/or interesting thing you learned in CHEM 1000?
…AND THAT’S ALL FOR CHEM 1000.
HAPPY HOLIDAYS!
[1 mark]
15
DATA SHEET
Fundamental Constants and Conversion Factors
Atomic mass unit (u) 1.660 539 × 10-27 kg
Avogadro's number
6.022 141 × 1023 mol–1
Bohr radius (a0)
5.291 772 × 10-11 m
Electron charge (e)
1.602 177 × 10-19 C
Electron mass
5.485 799 × 10-4 u
Ideal gas constant (R) 8.314 462 J·mol-1·K-1
8.314 462 m3·Pa·mol-1·K-1
Kelvin temperature scale
Planck's constant
Proton mass
Neutron mass
Rydberg Constant (RH)
Speed of light in vacuum
Standard atmospheric pressure
0 K = -273.15 ºC
6.626 070 × 10-34 J·Hz-1
1.007 277 u
1.008 665 u
2.179 872 x 10-18 J
2.997 925 x 108 m·s-1
1 bar = 100 kPa
Formulae
or
for aqua complexes
for oxoacids OpE(OH)q
Spectrochemical Series
strong field
weak field
4CN > ethylenediamine > NH3 > EDTA > H2O > oxalato > OH > F > Cl > Br > I
Band of Stability Graph
The graph at the right shows the band of stability.
Stable isotopes are in black. Isotopes that exist but
are not stable are shown in varying shades of gray
with the shades of gray corresponding to different
half-lives.
16
DATA SHEET
1
Chemistry 1000 Standard Periodic Table
18
1.0079
4.0026
H
He
2
13
14
15
16
17
6.941
9.0122
10.811
12.011
14.0067
15.9994
18.9984
Li
Be
B
C
N
O
F
Ne
3
22.9898
4
24.3050
5
26.9815
6
28.0855
7
30.9738
8
32.066
9
35.4527
10
39.948
1
2
20.1797
Na
Mg
11
39.0983
12
40.078
3
4
5
6
7
8
9
10
11
12
44.9559
47.88
50.9415
51.9961
54.9380
55.847
58.9332
58.693
63.546
65.39
K
Ca
Sc
Ti
V
Cr
Mn
Fe
Co
Ni
Cu
Zn
Ga
Ge
As
Se
Br
Kr
19
85.4678
20
87.62
21
88.9059
22
91.224
23
92.9064
24
95.94
26
101.07
27
102.906
28
106.42
29
107.868
30
112.411
31
114.82
32
118.710
33
121.757
34
127.60
35
126.905
36
131.29
Rb
Sr
37
132.905
38
137.327
Cs
Ba
55
(223)
56
226.025
Fr
87
Ra
Y
39
La-Lu
Ac-Lr
88
P
S
Cl
Ar
15
74.9216
16
78.96
17
79.904
18
83.80
Zr
Nb
Mo
Tc
Ru
Rh
Pd
Ag
Cd
In
Sn
Sb
Te
I
Xe
41
180.948
42
183.85
43
186.207
44
190.2
45
192.22
46
195.08
47
196.967
48
200.59
49
204.383
50
207.19
51
208.980
52
(210)
53
(210)
54
(222)
Hf
Ta
W
Re
Os
Ir
Pt
Au
72
(261)
73
(262)
74
(263)
75
(262)
76
(265)
77
(266)
78
(281)
79
(283)
Rf
Db
Sg
105
106
138.906
140.115
140.908
144.24
La
Ce
Pr
Nd
57
227.028
58
232.038
59
231.036
60
238.029
Ac
Si
14
72.61
40
178.49
104
89
25
(98)
Al
13
69.723
Th
90
Pa
91
U
92
Bh
107
Hs
Mt
Dt
Hg
Tl
Pb
Bi
Po
At
80
81
82
83
84
85
174.967
Rg
108
109
110
111
(145)
150.36
151.965
157.25
158.925
162.50
164.930
167.26
168.934
173.04
Pm
Sm
Eu
Gd
Tb
Dy
Ho
Er
Tm
Yb
Lu
61
237.048
62
(240)
63
(243)
64
(247)
65
(247)
66
(251)
67
(252)
68
(257)
69
(258)
70
(259)
71
(260)
Np
93
Pu
94
Am
95
Cm
96
Rn
86
Bk
97
Cf
98
Es
99
Fm
100
Md
101
No
102
Lr
103
Developed by Prof. R. T. Boeré