chemistry cp unit 2 atomic structure and electron ......1 chemistry cp unit 2 – atomic structure...

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Chemistry CP Unit 2 – Atomic Structure and Electron Configuration

Learning Targets (Your exam at the end of Unit 2 will assess the following:)

2. Atomic Structure and Electron Configuration

2-1. Give the one main contribution to the development of the atomic model from each of the following scientists: Dalton,

Thomson, Rutherford, Chadwick, and Bohr.

2-2. Identify elements by both name and chemical symbol using a periodic table.

2-3. Compare protons, electrons, and neutrons in terms of charge, mass, and location in an atom.

2-4. Use the periodic table to determine the number of protons, electrons, neutrons, and atomic mass for a given element.

2-5. Define isotope and state how the atomic structure for isotopes of the same element are similar and different.

2-6. Calculate the average atomic mass from the relative abundances and masses of each isotope.

2-7. Define valence electrons and determine the number of valence electrons for an atom.

2-8. Locate rows/periods and groups/families on the periodic table.

2-9. Draw the Bohr diagram for an atom showing protons and neutrons and the number of electrons in each shell. Draw the

Bohr diagram for the ion of an element, showing how the atom establishes a full valence shell. Determine the noble gas

that the atom resembles once it forms an ion.

2-10. Define ion and determine the charge for the ion of an element from the periodic table. Determine the number of

electrons for an ion. Give the symbol for the ion.

2-11. Define cation and anion.

2-12. List the four different kinds of atomic orbitals by their letter designation and state the number of electrons that each can

hold.

2-13. Give orbital notation for a given atom/ion.

2-14. Write electronic configuration for a given atom/ion.

2-15. Write noble gas configuration for a given atom/ion.

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2-1. Give the one main contribution to the development of the atomic model from each of the following scientists: Dalton,

Thomson, Rutherford, Chadwick, and Bohr.

Scientist Experiment Findings

Dalton

Thomson

Rutherford

Chadwick

Bohr

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2-2. Identify elements by both name and chemical symbol using a periodic table.

2-3. Compare protons, electrons, and neutrons in terms of charge, mass, and location in an atom.

2-4. Use the periodic table to determine the number of protons, electrons, neutrons, and atomic mass for a given element.

Subatomic Particles

Name Symbol Charge Relative Mass Actual Mass (g) Location

Symbol Name Atomic Number Mass Number Number of Protons

Number of Neutrons

Number of Electrons

𝑁𝑎1124

𝐵𝑟3580

𝐶𝑎2040

𝐴𝑢79197

34

78

22 47

91 231

𝑂2−8

16

𝐾+1939

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WS #1 (Learning Target 2-4. Use the periodic table to determine the number of protons, electrons, neutrons, and atomic mass for

a given element.

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WS #1 (con’t) (Learning Target 2-4. Use the periodic table to determine the number of protons, electrons, neutrons, and atomic

mass for a given element.

(11) Complete the following table for neutral atoms and/or ions.

Substance symbol

atomic

number

mass

number

number of

protons

number of

neutrons

number of

electrons Atom or ion?

Magnesium 12 24 12

Iron 26 24 atom

26 13 13

Sulfur S 16 16

Beryllium 9 atom

24 24 24

Platinum Pt+3 194 75

U+2 92 143

Oxygen O2- 8

18 18 -1 ion

Gold 118 78

45 24 22

74 70 +2 ion

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Substance symbol

atomic

number

mass

number

number of

protons

number of

neutrons

number of

electrons Atom or ion?

Magnesium Mg 12 24 12 12 12 atom

Iron Fe 26 50 26 24 26 atom

Aluminum Al 13 26 13 13 13 atom

Sulfur S 16 32 16 16 16 Atom

Beryllium Be 4 9 4 5 4 Atom

Chromium Cr 24 48 24 24 24 Atom

Platinum Pt+3 78 194 78 116 75 +3 ion

Uranium U+2 92 235 92 143 90 +2 ion

Oxygen O2- 8 16 8 8 10 -2 ion

Chlorine Cl- 17 35 17 18 18 -1 ion

Gold Au+ 79 197 79 118 78 +1 ion

Chromium Cr+2 24 45 24 21 22 +2 ion

Tungsten W+2 74 144 74 70 72 +2 ion

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2-5. Define isotope and state how the atomic structure for isotopes of the same element are similar and different.

2-6. Calculate the average atomic mass from the relative abundances and masses of each isotope.

Isotopes are atoms of the _____________ _________________ that have _______________ numbers of ______________.

Isotope Carbon-12 Carbon-13 Carbon-14

Atomic Number

Mass Number

Number of Protons

Number of Neutrons

Mass Number is the number of ________________ and _________________ in an atom.

Atomic Mass is the ______________________ _______________________ ___________________ of all the different isotopes of an

element ____________________ by the abundance of each isotope in nature.

Atomic mass is measured in Atomic Mass Units (_______)

(1 amu = 1/12 the mass of a carbon-12 atom)

Example: Silver (atomic number 47) has two naturally occurring isotopes, Ag-107 and Ag-109. Given their atomic masses and percent abundances below, what is silver’s average atomic mass?

Isotope Mass (amu) Abundance (%)

Ag-107 106.90509 51.84

Ag-109 108.90476 48.16

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Example: Silicon (atomic number 14) has three naturally occurring isotopes, Si-28, Si-29 and Si-30. Given their atomic masses and percent abundances below, what is silicon’s average atomic mass?

Isotope Mass (amu) Abundance (%)

Si-28 27.976927 92.23

Si-29 28.976495 4.67

Si-30 29.973770 3.10

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WS #2 (Learning Target 2-6. Calculate the average atomic mass from the relative abundances and masses of each isotope.)

(1) Isotopes are different “versions” of the same atom that have the same number of _____________ but different

numbers of _____________ and therefore different _____________ _____________.

(2) How many neutrons does each isotope have?

(a) Carbon-13 (b) Oxygen-18 (c) Potassium-40

(d) Scandium-45 (e) Manganese-55 (f) Tungsten-186

(3) There are two isotopes of copper: Copper-63 (69.17%) and Copper-65 (30.83%).

(a) Determine the number of neutrons in each of the isotopes.

(b) Calculate the average atomic mass of copper (round your answer to one decimal place).

(4) There are two isotopes of silver: Silver-107 (51.84%) and Silver-109 (48.16%).


(b) Calculate the average atomic mass of silver (round your answer to one decimal place).

(5) There are three isotopes of magnesium: Magnesium-24 (78.7%), Magnesium-25 (10.1%), and Magnesium-26 (11.2%)


(b) Calculate the average atomic mass of magnesium (round your answer to one decimal place).

(6) There are four isotopes of iron: Iron-54 (5.85%), Iron-56 (91.75%), Iron-57 (2.12%), and Iron-58 (0.28%)


(b) Calculate the average atomic mass of iron (round your answer to one decimal place).

(7) There are two isotopes of gallium: Gallium-69 and Gallium-71.


(b) Gallium-69 has an abundance of 60.11%, what is the abundance of Gallium-71?

(c) Calculate the average atomic mass of gallium (round your answer to one decimal place).

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WS #2 (con’t) (Learning Target 2-6. Calculate the average atomic mass from the relative abundances and masses of each isotope.)

(8) There are two isotopes of bromine: Bromine-79 and Bromine-81.


(b) Bromine-79 has an abundance of 50.69%, what is the abundance of Bromine-81?

(c) Calculate the average atomic mass of bromine (round your answer to one decimal place).

(9) There are five isotopes of germanium: Germanium-70, Germanium-72, Germanium-73, Germanium-74, and

Germanium-76


(b) Germanium-70 has an abundance of 21.23%, Germanium-72 has an abundance of 27.66%, Germanium-73

has an abundance of 7.73%, and Germanium-74 has an abundance of 35.94%. What is the abundance of

Germanium-76?

(c) Calculate the average atomic mass of germanium (round your answer to one decimal place).

(10) There are four isotopes of strontium: Strontium-84, Stronium-86, Strontium-87, and Strontium-88.


(b) Strontium-84 has an abundance of 0.56%, Strontium-86 has an abundance of 9.86%, and Strontium-87 has

an abundance of 7.00%. What is the abundance of Strontium-88?

(c) Calculate the average atomic mass of strontium (round your answer to one decimal place).

Answers: Isotopes (1) Isotopes are different “versions” of the same atom that have the same number of protons but

different numbers of neutrons and therefore different atomic masses (2) (a) 7 (b) 10 (c) 21 (d) 24 (e) 30 (f) 112 .

(3) (a) 34, 36 (b) 63.6 amu (4) (a) 60, 62 (b) 108.0 amu (5) (a) 12, 13, 14 (b) 24.3 amu (6) (a) 28, 30, 31, 32 (b) 55.9 amu

(7) (a) 38, 40 (b) 39.89% (c) 69.8 amu (8) (a) 44, 46 (b) 49.31% (c) 80.0 amu

(9) (a) 38, 40, 41, 42, 44 (b) 7.44% (c) 72.67 amu (10) (a) 46, 48, 49, 50 (b) 82.58% (c) 87.7 amu

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2-7. Define valence electrons and determine the number of valence electrons for an atom.

2-8. Locate rows/periods and groups/families on the periodic table.

2-9. Draw the Bohr diagram for an atom showing protons and neutrons and the number of electrons in each shell. Draw the Bohr

diagram for the ion of an element, showing how the atom establishes a full valence shell. Determine the noble gas that the

atom resembles once it forms an ion.

Periods on the periodic table go ______________ and __________________.

Groups on the periodic table go ______________ and __________________.

Valence Electrons =

How to determine the number of valence electrons an atom has:

Sample Problem. How many valence electrons? Carbon Magnesium Chlorine Helium

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WS #3 (Learning Target 2-9: Draw the Bohr diagram for an atom showing protons and neutrons and the number of electrons in

each shell. Draw the Bohr diagram for the ion of an element, showing how the atom establishes a full valence shell. Determine

the noble gas that the atom resembles once it forms an ion. )

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WS #4 (Learning Targets 2-10 and 2-11: Define ion and determine the charge for the ion of an element from the periodic table.

Determine the number of electrons for an ion. Give the symbol for the ion. Define cation and anion.)

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WS #4 (Learning Targets 2-10 and 2-11: Define ion and determine the charge for the ion of an element from the periodic table.

Determine the number of electrons for an ion. Give the symbol for the ion. Define cation and anion.)

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2-12. List the four different kinds of atomic orbitals by their letter designation and state the number of electrons that each can hold.

Orbital Letter Orbital Shape

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2-13. Give orbital notation for a given atom/ion.

2-14. Write electronic configuration for a given atom/ion.

2-15. Write noble gas configuration for a given atom/ion.

Order of Filling Orbitals:

Atom Atomic Number Number of Electrons

Orbital Notation _____ 1s

Electron Configuration

Noble Gas Configuration


Orbital Notation _____ 1s



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Orbital Notation _____ _____ 1s 2s




Orbital Notation




Orbital Notation




Orbital Notation




Orbital Notation



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Orbital Notation




Orbital Notation




Orbital Notation




Orbital Notation



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WS #5 (Learning Targets 2.13, 2.14, 2.15)

Complete the following table:

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(2) Give the orbital notation and electron configuration notation for the following elements:

(a) Sc (b) Fe

(c) Pd (d) Kr

(e) Ga (f) Co

(g) In (h) Cs

(i) Sn (j) Ce

(3) Give the electron configuration notation and noble gas notation for the following elements:

(a) Be (b) F

(c) Na (d) P

(e) Ti (f) Te

(g) Cd (h) Al

(i) La (j) Ac

(4) Give the orbital notation, electron configuration notation, and noble gas notation for the following elements/ions:

(a) V (b) Ge

(c) Y (d) Zn

(e) Sr (f) Rb+

(g) Ca2+ (h) Li+

(i) I – (j) N3–

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WS #6 (Unit 2 Review – part 1)

1. (Learning Target 2-1) Identify the main contribution each of the following made to the development of the atomic theory.

a. Dalton

b. Thomson

c. Rutherford

d. Chadwick

e. Bohr

2. (Learning Target 2-3) Compare protons, electrons, and neutrons in terms of charge, mass, and location in an atom.

Charge Relative Mass Mass (amu) Location

Proton 1

Neutron

Electron

3. (2-2, 2-4) Complete the following table for NEUTRAL atoms.

Atomic Number Element Symbol Atomic Mass Protons Electrons Neutrons (Show Your Work)

Fluorine

36

Os

112

4. (Learning Target 2-5) Among isotopes, which of the following are the same? Which are different?

Atomic Number?

Mass Number?

Atomic Mass?

# protons? # neutrons? # electrons?

5. (Learning Target 2-6) Calculate the average atomic mass from the relative abundances and masses of each isotope.

There are four isotopes of lead: Lead–204 (1.4%), Lead–205 (24.1%), Lead–207 (22.1%), and Lead–208 (52.4%).

(a) Determine the number of neutrons in each of the isotopes. Lead–204 = ________

Lead–205 = ________

Lead–207 = ________

Lead–208 = ________

(b) Determine the average atomic mass of Lead. Give the answer to one decimal place.

Average atomic mass = _________

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WS #9 (con’t) (Unit 2 Review – part 1)

6. (Learning Target 2-7, 2-9, 2-10) Draw the Bohr diagram for the atom and the ion. Indicate the number of protons,

electrons, and neutrons. Give the symbol and charge for the ion.

(a) boron ___ p ___ e ___ n symbol: ____ (b) chlorine ___ p ___ e ___ n symbol: ____

Atom:

Ion: Atom: Ion:

7. (Learning Target 2-10) Complete the following table for IONS.

Atomic Number

Element Symbol Atomic Mass Protons Electrons (Show Your Work)

Neutrons (Show Your Work)

Beryllium

51

Lu3+

210.1

8. (Learning Target 2-8) Where are periods located on the Periodic Table? Groups? Families?

9. (Learning Target 2-11) Distinguish between a cation and an anion.

10. (Learning Target 2-12) Draw a picture of one of each of the following orbitals.

Orbital Letter

Orbital Shape

s

p

d

f

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11. (Learning Targets 2-13, 2-14, 2-15)

(i) Give the orbital notation for the following elements.

(a) sodium (b) iron (c) europium

(ii) Give the electron configuration notation for the following elements.

(a) neon (b) bromine (c) thallium

(iii) Give the electron configuration for two possible excited states for neon.

(iv) Give the noble gas notation for the following elements.

(a) fluorine (b) titanium (c) americium

(v) Give the electron configuration notation and noble gas notation for the following ions.

(a) O2- (b) Y3+

Answers: (1) (a) developed the atomic theory (b) discovered the electron in his cathode ray experiment, developed plum pudding

model (c) discovered the nucleus in his gold-foil experiment (d) discovered the neutron (e) developed the orbital model of the atom

(2)

Charge Relative Mass Mass (amu) Location

Proton +1 1 1 nucleus

Neutron 0 1 1 nucleus

Electron -1 1/1836 0 Outside of nucleus

(3)

Atomic Number Element Symbol Atomic Mass Protons Electrons Neutrons (Show Your Work)

9 Fluorine F 19.00 9 9 10

36 Krypton Kr 83.80 36 36 48

76 Osmium Os 190.23 76 76 190 – 76 = 114

112 Copernicium Cn 285 112 112 4 – 112 = 173

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(4) same atomic number, different mass number, different atomic mass, same # protons, different # neutrons, same # electrons

(5) (a) 122, 123, 125, 126 (b) 207.0 amu (6) (a) 5p, 5e, 6n (b) 17p, 17e, 18n

(7)

Atomic Number

Element Symbol Atomic Mass Protons Electrons (Show Your Work)

Neutrons (Show Your Work)

4 Beryllium Be2+ 9.012 4 4 – 2 = 2 5

51 Antimony Sb3- 121.76 51 51 + 3 = 54 71

71 Lutetium Lu3+ 174.97 71 71 – 3 = 68 104

85 Astatine At- 210.1 85 85 + 1 = 86 125

(8) periods – horizontal rows, groups (aka families) – vertical columns (9) cation = positive ion, anion = negative ion

(10)

Orbital Letter

Orbital Shape

s

p

d

f

(11) (i)

(ii) (a) 1s2 2s2 2p6 (b) 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p5 (c) 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p1

(iii) answers will vary; Sample examples: 1s2 2s2 2p5 3s1 or 1s2 2s2 2p5 3p1 (iv) (a) [He] 2s2 2p5 (b) [Ar] 4s2 3d2 (c)

[Rn] 7s2 5f7 (v) (a) 1s2 2s2 2p6 , [Ne] (b) 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 , [Kr]

chemistry cp unit 2 atomic structure and electron ......1 chemistry cp unit 2 – atomic structure...

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