Download Chemistry - Isotopes

UNIT 2 PART B – OBJECTIVES
Recall that Unit 2 includes chapters 3 and 4 from the text.
At the conclusion of this unit, students will be able to:
Describe the historical progression of the atomic theory (AT).
Explain that science exists in a historical context.
Relate the development of the AT to its historical context.
Describe individuals and their contributions to the AT.
State the four ideas of Dalton’s AT.
Describe, in some technical detail, Thomson’s work with CRT’s.
Describe, in some technical detail, Millikan’s oil drop experiment.
Describe, in some technical detail, Rutherford’s gold foil experiment.
Describe the various models of the atom.
Describe similarities and differences of isotopes.
Determine atomic #, mass #, and particles in assigned isotopes.
Determine names and symbols of isotopes.
Determine average atomic mass of an element.
Explain relative abundances of isotopes.
Calculate formula mass.
Define mole, and state Avogadro’s number.
Solve for moles and/or mass and/or number of particles.
Describe and sketch the electromagnetic spectrum.
Label the spectrum ends with regard to E, ν, λ.
Identify forms of EM radiation in regard to higher/lower E, ν, λ.
State and describe the speed of light.
Solve problems, calculating c, E, ν, λ.
State and discuss specific uses of EM.
Define spectroscopy.
Use spectra to identify substances.
Define and describe quantum numbers.
Name and describe each of the quantum numbers.
State possible values of each quantum number.
Define orbital.
Describe shapes and sizes of various orbitals.
State quantum numbers for particular orbitals/electrons.
State and apply the Aufbau Principle.
State and apply Hund’s Rule.
State and apply the Pauli Exclusion Principle.
Complete an orbital filling diagram.
Write the electron configuration of a given atom.
Identify the valence electrons in an electron configuration.
Draw electron dot diagrams.
RIDICULOUSLY TINY WORKSHEET…
1. Atoms are ______________________________ tiny.
2. Use page 151 to find the radius of a helium atom: ________________________________
3. The DIAMETER of a helium atom is: __________________________
4. Express the DIAMETER of a helium atom in meters, in scientific notation: ______________________.
5. A quarter is 1.75mm thick. Determine the number of quarters in a stack that would reach the moon, which is 200 000 miles away:
6. Now, find the number of helium atoms that would be needed, side-by-side, to span this room (approximately _______ meters):
7. (YOUR TURN) Determine the length (width, etc.) of an ordinary object.
______________________________________
____________________________
8. Choose an appropriate type of atom: ______________________ and radius: __________________
9. Now, compute the length, from 7, in atoms:
10. Prepare a nice illustration of this!
THE ATOM
1. Atoms are composed of: _____________________, ____________________, and _________________.
2. Complete the table of subatomic particles:
NAME
SYMBOLS
CHARGE
MASS
NUMBER
RELATIVE
MASS (amu)
WHERE FOUND
3. Define ATOMIC NUMBER:
4. Define MASS NUMBER:
5. Imagine an atom composed of 15 protons, 15 electrons, and 16 neutrons. Complete the following:
atomic number: ________
mass number: ________
Identify this atom: __________________________________ Symbol: ____________
6. Now, imagine an atom composed of 15 protons, 15 electrons, and 17 neutrons. Complete the following:
atomic number: ________
mass number: ________
Identify this atom: __________________________________ Symbol: _____________
7. 31P and 32P are two ______________________ of phosphorous.
8. Name the atom (isotope) that contains 20 protons, 20 electrons, and 22 neutrons:
Name: __________________________________ Symbol: _____________
9. Name the atom (isotope) that contains 47 protons, 47 electrons, and 52 neutrons:
Name: __________________________________ Symbol: _____________
Chemistry - Isotopes
1. Define: isotope
2. Define:
atomic number -
mass number -
3. Complete the chart of isotopes:
Name
symbol atomic #
mass #
# protons # electrons
# neutrons
Sulfur-35
Lithium-7
31
P
22
24
122
238
52
U
17
21
212
Po
42
4. Define: average atomic mass -
55
FORMULA MASS AND MOLAR CONVERSIONS
1. Read the assigned portion of the text.
2. Define:
FORMULA MASS
3. Compute the formula masses for each of the following:
A. Ga
B. U
C. NH3
D. Na3PO4
E. SCl6
F. (NH4)2CO3
4. Compute the number of moles in each:
A. 1.42g Ga
B. 3.11 X 10-3g U
C. .022g NH3
D. 453.2g Na3PO4
E. 2.7 X 10-7g SCl6
F. 4.33g (NH4)2CO3
5. Compute the mass of:
A. 2.17 X 10-4 mol MgF2
B. .622 mol K2CO3
C. 5.40 X 104 mol NaCl
D. 8.41 mol C6H12O6
6. WE MUST ALWAYS GO THROUGH _______________________!!!!!
7. Calculate the mass of:
A. 3.011 X 1022 atoms U
B. 4.55 X 1017 molecules NH3
C. 4.53 mol H2O2
D. 5.09 X 1019 molecules PCl5
8. Find the number of particles (and identify type) present in:
A. 4.33g Li2SO3
B. 7.63 X 10-4 g CaCl2
C. 4.66 kg CH2O
D. 5.40 X 105 mol KBr
MOREMOLE…
1. WE MUST ALWAYS GO THROUGH _______________________!!!!!
2. Compute the number of moles in each:
A. 3.55g Ca
B. 5.04 X 1021 atoms Mn
C. 2.7 X 1018 molecules SF2
D. 7.114g Ca(NO3)2
3. Calculate the mass of:
A. 2.5 X 1025 atoms C
B. 2.47 X 1022 molecules H2O
C. 2.005 mol N2O4
D. 9.22 X 1021 molecules SeCl4
4. Find the number of particles (and identify type???) present in:
A. 12.11g Fe2S3
B. 3.49 X 10-4 g BaF2
C. 4.66 kg CO2
D. 5.40 X 105 mol KBr
MOCK (old B) Quiz
Name:_________________________
1. Compute the number of molecules in 1.178g PCl3:
2. Compute the mass of 4.77 X 1025 molecules of NF3:
_____3. Copper is composed of two isotopes, copper-63 and copper-65. Which isotope is more common?
A. copper-63
B. copper-65
C. They are equally abundant
D. Additional information is needed.
4. Complete the table below:
Name
Symbol
atomic #
mass #
25
55
# protons
# electrons
# neutrons
Silicon-30
18
O
80
122
Solve the following problems, being careful to:
1. Show all work
2. Include all units, etc.
3. Keep all work neat and organized.
1. The world population is estimated at 6.79 X 109. If the average person
speaks 3.5 X 103 words per day, how many words are spoken in a year?
2. If 6.022 X 1023 atoms of copper have a mass of 63.546g, determine the
mass of 5.00 X 105 L of copper.
FIX PROBLEM BELOW????
3. Determine the number of particles (molecules) exhaled in one breath,
given that the volume of a breath is 2.5L. 2.24 X 104 ml of air is known
to have a mass of 2.9 X 10-2 kg, and the density of air is 1.29 X 10-3 g/ml.
4. What would it cost to buy a single atom of aluminum, if aluminum costs
$3.20 per pound, and 6.022 X 1023 atoms of aluminum have a mass of 26.982g?
TEST REVIEW – There area series of problems and other items to help you review. That is followed by an actual mock test, with
answers.
Extra practice: moles and EM
1. Calculate the frequency of radio waves of a wavelength of 1.50cm.
2. Calculate the wavelength of UV with a frequency of 9.0 X 1015 Hz.
3. Calculate frequency of gamma rays with wavelength of 5.0 X 10-3 nm.
4. In order to communicate with subs that are deep underwater, the
navy must use radio waves of an extremely long wavelength. One antenna,
buried in the northern US, is approximately 30 kilometers long! Assuming
these waves have a wavelength of 30.0 km, calculate the frequency of these
radio waves:
5. Calculate the energy of one photon of ultraviolet that has a
frequency of 6.77 X 1016 Hz.
6. Calculate the energy of a radio photon of a wavelength of 32cm.
7. Describe the process (steps) by which an atom emits a photon (of
visible light).
8. If an atom emits visible light at 450nm, what is the energy of the
electronic transition (electron change) causing this emission?
9. What is the frequency of electromagnetic radiation corresponding
to an electron transition of 7.39 X 10-14 J? What type of EM is this?
1. 2.00X1010 cm/s 2. 3.3X10-8 m 3. 6.0X1019 1/s 4. 1.00X104 1/s 5. 4.49X10-17 J
6. 6.2X10-25 J 7. e- absorbs E, is in excited state. e- releases excess E as a photon as it goes to lower E.
8. 4.42X10-19 J
10. 1.12X1020 1/s gamma
1. Calculate the mass of 3.2 mol water.
2. Determine the number of formula units in .25 mol FeCl3.
3. How many atoms are present in .032g sulfur?
4. Determine the mass of 1.2 X 1017 molucules CH4.
5. Calculate the number of molecules in 3.6g glucose (C6H12O6).
6. Calculate the mass of 9.0X 1026 formula units Ca(NO3)2.
1. 58g water 2. 1.5 X 1023 formula units FeCl3.
3. . 6.0 X 1020 atoms S 4. 3.2 X10-6g CH4
5. 1.2 X 1022 molecules C6H12O6
6. 2.5 X 105 g Ca(NO3)2
1. Calculate the mass of 3.2 mol water.
2. Determine the number of formula units in .25 mol FeCl3.
3. How many atoms are present in .032g sulfur?
4. Determine the mass of 1.2 X 1017 molucules CH4.
5. Calculate the number of molecules in 3.6g glucose (C6H12O6).
6. Calculate the mass of 9.0X 1026 formula units Ca(NO3)2.
1. 58g water 2. 1.5 X 1023 formula units FeCl3.
3. . 6.0 X 1020 atoms S 4. 3.2 X10-6g CH4
5. 1.2 X 1022 molecules C6H12O6
6. 2.5 X 105 g Ca(NO3)2
1. Calculate the mass of 3.2 mol water.
2. Determine the number of formula units in .25 mol FeCl3.
3. How many atoms are present in .032g sulfur?
4. Determine the mass of 1.2 X 1017 molucules CH4.
5. Calculate the number of molecules in 3.6g glucose (C6H12O6).
6. Calculate the mass of 9.0X 1026 formula units Ca(NO3)2.
1. 58g water 2. 1.5 X 1023 formula units FeCl3.
3. . 6.0 X 1020 atoms S 4. 3.2 X10-6g CH4
5. 1.2 X 1022 molecules C6H12O6
6. 2.5 X 105 g Ca(NO3)2
Summary: ELECTRONIC STRUCTURE
The electromagnetic spectrum can be divided into seven forms of energy.
entire spectrum, including THREE labels for each end:
Here, draw the
All forms of EM travel at “the speed of ______________,” abbreviated ___, which has
the value _________________. The formula relating wavelength and frequency of EM
radiation is ___________, where ν = _____________ and γ= _____________.
The energy of EM radiation is directly related to its ______________, and can be
computed from the formula ____________, where h is ___________ constant, which has the
value ________________. Max __________ stated this as the _____________ theory: Energy
is not given off continuously, but in discrete packets called ________, or, when
referring to radiant (EM) enetgy: ___________________.
Define spectroscopy:
The field of spectroscopy is based on the fact that electrons do NOT absorb/emit
all energies, but instead absorb/emit certain, specific, (and unique) energies of EM
radiation. Neils ___________ interpreted the definite energies given off by electrons as
an indication that atomic electrons exist at (possess) definite energy levels, or
____________. The lowest energy level for a given electron is called the ________ state,
and all higher energy levels are called _______________ states. When an electron “moves”
from a higher to a lower energy level, it _____________ one “package” (_________, or
__________) of EM radiation.
Bohr’s model is commonly called the _______________ model, because he assumed the
_______________ orbited around the ____________, like planets around the sun. This
portion of Bohr’s theory is _______ correct, as shown by _______________, who stated that
the ______________ and ______________ of an electron cannot both be precisely known.
Planck’s ____________ theory attributed to light a ______________ nature, in
addition to its wave nature. Louis de Broglie then turned this around and suggested that
particles also exhibit some of the characteristics of ____________. These two ideas
together are referred to as the _________-______________ duality of ______________. The
wave nature of visible particles is negligible. The wave nature of a particle is only
important if the particle’s mass is very ____________, or if the particle is moving very
______________.
Erwin ___________________ realized that the electrons in an atom could be better
described as _______ than as particles. Schrődinger’s equation can be solved forΨ (psi),
the wave function, which (when squared) describes the ________________ of finding the
electron within a given volume of space.
Solutions to Schrődinger’s equation are not a single value, but each solution is a
series of four numbers (n,l,m,s), referred to as _________________ numbers. Each
electron in an atom is described by a unique set of four quantum numbers. State the
Pauli Exclusion Principle:
In a set of four quantum numbers, the first three describe the __________ nature of
the electron, and describe a particular _______________ (or or electron wave or electron
cloud). The fourth quantum number describes the _________ of the electron. Two
electrons occupying the same orbital have ______________ spins.
Single electrons in a degenerate (same energy) set of orbitals have the __________
spin (known as Hund’s Rule).
Also review: the Aufbau Principle and the Pauli Exclusion Principle.
Determine electron configurations for: Li,C, O, Mg, Si, S, Ar, I, and Rn.
Show electron dot diagrams for each of the atoms above.
MOCK TEST UNIT2B -- CHEMISTRY TEST
ATOMIC STRUCTURE AND THE MOLE
NAME:_______________________
1. The chemistry (chemical behavior) of an atom is determined by its:
A. protons
B. neutrons
C. electrons
2. Which is no longer viewed as a correct model of the atom?
A. electron cloud model
B. quantum-mechanical model
C. planetary model
D. probability model
3. The "addresses" of electrons are composed of ___ quantum numbers.
A. 1
B. 2
C. 3
D. 4
4. The second quantum number is referred to as the ________ quantum number.
A. angular momentum
B. spin
C. magnetic
D. principal
5. The fourth quantum number is referred to as the ________ quantum number.
A. angular momentum
B. spin
C. magnetic
D. principal
6. The ________ quantum number indicates the energy sublevel.
A. angular momentum
B. spin
C. magnetic
D. principal
7. The ________ quantum number indicates the orbital direction.
A. angular momentum
B. spin
C. magnetic
D. principal
8. The ________ quantum number indicates the orbital size.
A. angular momentum
B. spin
C. magnetic
D. principal
9. The ________ quantum number indicates the orbital shape.
A. angular momentum
B. spin
C. magnetic
D. principal
10. Of the following orbitals, which is lowest in energy?
A. 2p
B. 3p
C. 3d
D. 2s
11. Any given orbital can contain a maximum of ___ electrons.
A. 2
B. 4
C. 6
D. 8
12. The 3p sublevel can contain ___ electrons.
A. 2
B. 6
D. 10
13. What is the shape of a d orbital?
A. spherical
B. dumbbell
C. 8
C. double dumbbell
14. "Orbital" refers to the electron _________.
A. cloud
B. wave
C. either A or B
D. none of the above
15. Which orbitals do electrons fill first?
A. lowest energy
B. highest energy
C. energy is not a factor in which orbitals are filled first
16. Which orbitals do electrons fill first?
A. closest to the nucleus
B. farthest from the nucleus
C. nuclear proximity does not affect orbital filling
17. The four quantum numbers (n,l,m,s) for a particular electron are as follows:
(3,2,0,1/2). This electron is in a _____ orbital:
A. 2s
B. 1s
C. 3d
D. 3p
18. A total of ____ electrons can be on the fourth energy level.
A. 8
B. 16
C. 18
D. 32
19. d orbitals occur in sets of _____.
A. 3
B. 4
C. 5
D. 7
20. Iron is a(n) ___ block element.
A. s
B. p
C. d
D. f
21. The highest energy electron in an atom of barium is in a(n) _____orbital.
A. s
B. p
C. d
D. f
22. "No two electrons in the same atom can have the same four quantum numbers." was first
stated by ___________.
A. Hund
B. de Broglie
C. Schrodinger
D. Pauli
23. 1s2 2s2 2p6 3s2 is the electron configuration for an atom of ___.
A. Mg
B. Ca
C. Cl
D. Si
24. Which of the following is the correct (sloppy…) electron configuration for a neutral
atom of antimony?
a)
b)
c)
d)
1s2
1s2
1s2
1s2
2s2
2s2
2s2
2s2
2p6
2p6
2p6
2p6
3s2
3s2
3s2
3s2
3p6
3p6
3p6
3p6
4s2
4s2
4s2
4s2
3d10
3d10
3d10
4d10
4p6
4p6
4p6
4p6
4d10 5p5
5s2 4f13
5s2 4d10 5p3
5s2 5d10 5p3
25. Which of the following indicates the correct sequence for electron filling of the
indicated orbitals?
A. 4s, 3p, 3d, 4p
B. 3d, 4s, 3p, 4p
C. 3p, 3d, 4s, 4p
D. 3p, 4s, 3d, 4p
26. ______ stated that electrons will half-fill a set of orbitals of the same energy
before "pairing up."
A. Hund
B. de Broglie
C. Schrődinger
D. Pauli
27. If two electrons are in two different orbitals of the same energy, such as
2py, their spins are:
A. the same
B. opposite
C. it doesn't matter
2px and
28. If two electrons are in the same orbital, their spins are:
A. the same
B. opposite
C. it doesn't matter
29. The chemistry (chemical behavior) of an atom is determined by its:
A. protons
B. neutrons
C. electrons
30. The chemical behavior of an atom is most affected by its _________ electrons.
A. inner
B. outer
C. All electrons have the same effect.
31. An atom of chromium-52 contains ___ neutrons.
A. 4
B. 24
C. 28
D. 52
32. The average atomic mass of gallium is 69.72 amu. Atoms of gallium contain:
A. .72 of a proton
B. .72 of a neutron
C. .72 of an electron
D. none of the above
33. Boron is composed of two isotopes, boron-10 and boron-11. The average atomic mass of
boron is 10.811 amu. How do the natural abundances of the two isotopes compare?
A. Boron-11 is more abundant
B. The abundances are the same
C. Boron-10 is more abundant
D. Can't be determined from the given data
34.
The average atomic mass of titanium is _____.
35. The correct units for the prior answer could be:
A. amu
B. u
C. g/mol
A. 22
B. 47
C. 48
D. all of the above
36. The number of objects in a mole is referred to as ___________ number.
A. Avogadro's
B. Boyle's
C. Chadwick's
D. Dalton's
37. The "building blocks" in a sample of iron would be called:
A. formula units
B. atoms
C. molecules
D. 47.88
38. One mole of water:
A. contains 6.02 X 1023 molecules of water.
B. has a mass of 18.0 grams.
C. contains one mole of oxygen atoms and 2 moles of hydrogen atoms.
D. all of the above.
39. Which of the following is the correct (sloppy) electron configuration for a Te+1 ion?
HINT: An ion is a charged particle. In this case, the ion is an atom that has gained or
lost a small number of electron(s).
a)
b)
c)
d)
1s2
1s2
1s2
1s2
2s2
2s2
2s2
2s2
2p6
2p6
2p6
2p6
3s2
3s2
3s2
3s2
3p6
3p6
3p6
3p6
4s2
4s2
4s2
4s2
3d10
3d10
3d10
4d10
4p6
4p6
4p6
4p6
4d10 5p5
5s2 4d10 5p3
5s2 4d10 5p5
5s2 5d10 5p5
40. Which of the following is the correct (sloppy) electron configuration for an atom of
silver?
a)
b)
c)
d)
1s2
1s2
1s2
1s2
2s2
2s2
2s2
2s2
2p6
2p6
2p6
2p6
3s2
3s2
3s2
3s2
3p6
3p6
3p6
3p6
4s2
4s2
4s2
4s2
3d10
3d10
3d10
3d10
4p6
4p6
4p6
4p6
4d10 5p1
5s2 4d9
5s1 4d10
4d9 5p2
PROBLEMS -- Show ALL work!!!!
1. Compute the number of moles present in 1.2 X 1027 molecules of C2H6O.
2. Compute the number of moles present in .0641g of Sulfur.
3. Compute the mass of 4.5 X 1018 molecules of sulfur dichloride (SCl2).
4. Gallium exists as two isotopes, gallium-69 and gallium-71. Gallium-69 has a
mass of 68.926 amu and is 60.32% of naturally occurring gallium. The other
39.68% is gallium-71, which has a mass of 70.926 amu. Compute the average atomic
mass of gallium.
5. Calculate the wavelength of UV waves with a freguency of 9.00 X 1017 Hz:
6. Calculate the frequency x-rays that have a wavelength of 4.5 X 10-4nm:
7. Calculate the energy of radio photons with a wavelength of 6.0 cm:
8. Show the complete electron configurations of the following atoms:
REMEMBER: Try to do so WITHOUT the energy level diagram!!!
A. Carbon
B. Magnesium
C. Silicon
D. Manganese
9. Show the shorthand electron configuration and box notation for Al.
10. Show the electron dot structures for:
N, K, S, Ar
MOCK TEST – UNIT 2B – ANSWERS
1-10 C C D A B A C D A D
11- 20 A B C C A A C D C C
21- 30 A D A C D A A B C B
31 – 39 C D A D D A B D B
40 is C, which is an exception to what we would predict.
won’t ask about exceptions on the test.
Don’t worry about why, and I
1. 2.0 X 102 mol C2H6O.
2. .00200 mol S
3. 7.7 X 10-4 g SCl2.
4. 69.72u
5. 3.33X10-10m
6.
6.7X1020 Hz
7. 3.3X10-24 J
8. See the textbook
9. [Ne] 3s23px1
Don’t worry about box notation (just like orbital
notation, in the text)
10. See the text