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Chemistry I - Unit 4: Chapters 5-6 - Periodic Table and Characteristics of Elements
Vocab Quiz: Friday, Oct. 3
Test Date: Wednesday, Oct. 8
Vocabulary:
average atomic mass
metal
Mendeleev
ionization energy
alkali metals
actinides
EQs/PS Due: Wednesday, Oct. 8
atomic number
nonmetal
valence electrons
periodic law
alkaline earth metals
halogens
mass number
metalloid
ionic radius
electronegativity
transition metals
noble gases
period
family
atomic radius
electron affinity
lanthanides
OBJECTIVES:
 Identify groups as vertical columns on the periodic table.
 Know that main group elements in the same group have similar properties, the same number of valence
electrons and the same oxidation number.
 Understand that reactivity increases as you go down within a group for metals and decreases for nonmetals.
 Identify periods as horizontal rows on the periodic table.
 Identify representative (main group) elements as groups 1, 2, 13-18.
 Identify alkali metals, alkaline earth metals, halogens, and noble gases based on location on periodic table.
 Identify transition elements as groups 3-12.
 Use a periodic table to write the symbols of elements, given their names.
 List the characteristics that distinguish metals, nonmetals, and metalloids.
 Assign the oxidation number for elements and each element in the formula of a chemical compound.
 Define valence electrons and state how many are present in atoms of each main-group element.
 Locate and name the four blocks of the periodic table and explain the reasons for these names.
 Understand how the periodic table is set up.
 Be able to list and describe the four quantum numbers.
 Be able to define above vocabulary
 Given a set of at least 4 elements, be able to place them in order of increasing/decreasing periodic properties.
 Be able to order ions and atoms by size.
 Be able to identify the families on the periodic table.
EQS: Review:
Day 1 - Review:
 Find the mass of an element if out of a sample of 100:
 5 % have a mass of 176, 19 % have a mass of 177, 27 % have a mass of 178, 14 % have a mass of 179 and 35 % have a
mass of 180?
 Identify this element by symbol and name.
 Copy and fill in the following table:
Element/ion
Fe
K+
# of protons
# of neutrons
# of electrons
27
25
O2Strontium-89
Day 2 – New Material
 List 4 characteristics of metals.
 List 4 characteristics of non-metals.
 List the family for each of the following:
A. Sr
B. Ar
C. Cl
D. K
E. O
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Day 3 


Day 4 

Why is Si bigger than S (explain why – do not just write because it is further left!)
Why is Se bigger than S? (explain why)
Why is Cu2+ smaller than Cu?
Identify the two ions that are most important in the human body. Where are they found? What is their function?
Given Al, I and F
a. Place them in order of increasing electronegativity
b. Place them in order of decreasing ionization energy
c. Place them in order of increasing atomic size
Day 5 –
 Consider two main-group elements, A and B. Element A has an ionization energy of 419 kJ/mol. Element B has an
ionization energy of 1000 kJ/mol. Which element is more likely to form a cation? Explain.
 Among the main-group elements, what is the relationship between group number and the number of valence electrons among
group members?
 Why is iodine placed just after tellurium on the periodic table even though its atomic mass is less than the atomic mass of
tellurium?
The Periodic Table
Answer the following questions as you read Chapters 5 & 6
1. What scientist is credited with developing the first periodic table?
2. What does the term periodic mean?
3. Who is credited with the development of the atomic number?
4. What is the periodic law?
Remember elements in the same family have similar chemical properties!
5. Define a group/family.
6. Indicate where the following are located on the periodic table.

metals

non-metals

metalloids
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Before we talk about other type of notations we have to discuss:
valence electrons (outer electrons) – electrons in the outermost energy level. (participate in bonding!)
inner-shell electrons – electrons not in the highest occupied energy level.
Lewis Dot Diagram: a third way to represent electron configurations using valence electrons.
Step 1: Draw e- configuration & orbital notation.
Step 2: Allow element symbol to represent inner e-s.
Step 3: Use dots for valence e-s.
a. It is important to pair e-s correctly.
b. It is not important which side of the element symbol the dots are placed.
Examples:
H
Se
Pd
You try:
Mg
Sb
Xe
The above examples are “typical” electron configurations – there are exceptions – when an arrangement leads to a filled d-level or
half-filled d level for example:
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Cr is expected to have the configuration of [Ar]4s23d4 but actually has the configuration of [Ar]4s13d5 because it is more stable to have
half-filled orbitals.
( We will not be working with these types of configurations at this level.)
PERIODIC PROPERTIES
We will not be working with the lanthanoid
or actinoid families in these problems
I. ATOMIC SIZE (atomic radius)
Here is some data about the sizes of atoms.
Graph Period 2’s data on the graph below.
In a different color, graph Period 3’s data
on the graph below.
Note: Mark the vertical axis
from 0 – 160 (by 20’s)
Trend in Atomic Size Across the Periodic Table
Li
Na
Be
Mg
B
Al
C
Si
N
P
O
S
Horizontal Trend (period trend – remember same period = same # of energy levels)
F
Cl
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What is the trend in atomic size as you go across the periodic table? _______________________________
This is true because there are more _____________________ (protons / layers of electrons) pulling the electron cloud in toward the
nucleus.
This is true because nuclear pull increases across the periods (due to the fact that there in more nuclear pull due to the increase in the
# of protons)
Vertical Trend (Family trend- most important)
Examine the sizes of the Group 1 elements (H, Li, Na, K, Rb, Cs). What is the trend in atomic size as you go down a column of the
periodic table? ________________________________________
This is true because there are more ______________________ (protons / layers of electrons) making the electron cloud larger.
To go from biggest to smallest atom start at the bottom left (Fr) and go across the rows working from the left to right and then going
up – Mrs H will demonstrate.
Together: Put in order by increasing size:
Li O
Si Ar and N
With partner: Place in order of increasing size:
K P
As
Na
F
Practice # 2 Place in order of decreasing size:
K
Mg
Sc
Ba
II. Ionization energy (first) - The energy required to remove one electron from a neutral atom of an element, measured in
kilojoules/mole (kJ/mol)
Here is some data about the first ionization energy of atoms. Graph Period 2’s data on the graph below. In a different color, graph
Period 3’s data on the graph below. (kJ/mol)
1
2
3
4
5
6
1
H
1312
Li
520
Na
496
K
419
Rb
2
13
14
Be
899
Mg
738
Ca
590
Sr
B
801
Al
578
Ga
C
1086
Si
786
Ge
In
Cs
Ba
Tl
15
16
17
N
1402
P
1012
As
O
1314
S
1000
Se
F
1681
Cl
1251
Br
18
He
2372
Ne
2081
Ar
1521
Kr
Sn
Sb
Te
I
Xe
Pb
Bi
Po
At
Rn
Ionization Energy
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Note: Mark the vertical axis from 400 – 2400 (in 200s)
GENERAL Trend in Ionization energy Across the Periodic Table
Li
Na
Be
Mg
C
Si
F
Cl
Ne
Ar
Horizontal trend (period trend –most important)
What is the trend as you go across the periodic table? ___________________
This is true because nuclear pull increases across the periods (due to the fact that there in more nuclear pull due to the increase in the #
of protons)
Vertical trend (family trend)
Examine the group 1 elements (or the noble gases) What is the trend in IE as you go down a column of the periodic table?
______________________
Shielding effect: outer electrons are shielded from the pull of the nucleus by the inner shell electrons. e- on a higher energy level are
further from the nucleus and have less nuclear pull = easier to remove.
To go from the largest IE to the smallest start at the top right (He) and go down the columns working from right to left –
Together: Put the following in decreasing order of ionization energy
F
Cl
Mg
Sr
P
You Try: Put the following in order of increasing IE
Na
Te
S
Li
III. Electron Affinity - the attraction of an atom for an electron
Period Trends (most important): e- affinity increases across the table from ___________________ to ______________________
Group Trends: electron affinity increases _______________________ the group.
(Trend is the same as trend for IE for the same reasons!) Start with He as the largest
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Practice: Place the following in order of decreasing e- affinity
Mn
Br
S
Rb
Fe
IV. Electronegativity : the attraction of an atom in a compound for an electron
(Does not include the Noble Gases – Why?)
Period Trends (most important)- increases across the period
Group Trend: electonegativity increases ___________________ a group.
Trend is the same as IE and electron affinity!!
Least electronegative family _____________________ ; most electronegative family __________________________ .
Most electronegative element:______________________ ; Least Electronegative element:______________________
Practice: Place in order of increasing electronegativity:
W
Bi
I
Rb
As
V. Ionic Radius – tells us the size of the ions
Cations = _______________ ions
Anions= ________________ ions
Cations: ___________________ e-s (therefore have ____________________ charge) they are smaller than their parent atom
Ex: Na+ is smaller than Na
Anions: ______________________e-s (have _______________________ charge) they are larger than their parent atom.
Ex: Cl-1 is larger than Cl
Practice: Which is larger?
Ca or Ca2+
N or N3-
Al3+ or Al
C4- or C or C4+
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VI.
Reactivity:
Metals: most reactive ___________ and _______________
Nonmetals more reactive ____________ and _______________ (Except Noble gases- Why?)
Practice:
Circle the most reactive metal:
Au
Cs
Sr
Ti
Circle the most reactive nonmetal:
Se
Cl
O
Ne
P
PRACTICE ALL TRENDS!
Given Li, Ca, S, I Put the elements in order of:
A. Increasing ionization energy
B. Decreasing Atomic radius
C. Increasing electron affinity
D. Decreasing electronegativity
Diagrams of Periodic Trends: Using the following diagrams, draw in the indicated Periodic Trend
Atomic Radius
Ionization Energy
Electronegativity
Melting/Boiling Point
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Periodic table worksheet
1. Where are the most active metals located? _______________ What is the most active metal? _______________
2. Where are the most active nonmetals located?____________ What is the most active nonmetal?_____________
3. Where are the least active elements located? _______________
4. As you go from left to right across a period the atomic size (decreases/increase) Why?
______________________________________________________________________________
5. As you travel down a group, the atomic size (decreases/increases) Why?
_____________________________________________________________________________________
6. A negative ion is (larger/smaller) than its parent atom
7. A positive ion is (larger/smaller) than its parent atom
8. Circle the largest atom in this group:
Ba
K
I
P
9. As you go from left to right across a period, the first ionization energy generally (decreases/increases) why?
_________________________________________________________________________________________
10. As you go down a group, the ionization energy generally (decreases/increases) Why?___________________________
11. What family has the highest electronegativity?
Circle the largest electronegativity:
Ba
K
I
P
12. Elements of group I are called__________________ group 2 ______________ group 3- 12 _______________
13. As you go from left to right across the periodic table the elements go from (metals/nonmetals) to (M /NM)
14. Group 17 is called __________
15. The most active element in group 17 is ____________
16. Group 18 elements are called ____________
17. What sublevels are filling across the transition elements?_________
18. Elements within a family has a similar number of _______________
19. Elements across a period have the same number of ______________________
20. A colored ion generally indicates a transition metal – when naming most transition metals you need to use _________________
21. As you go down a group, the elements generally become (more/less) metallic
22. The majority of elements in the periodic table are (metals/nonmetals)
23. Elements in the periodic table are arranged according to their _______________
24. An element with both metallic and nonmetallic properties is called a _____________
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Review sheet: Periodic table and Periodic Properties
1. Given: C Mg S Ba place these elements in order of:
A. increasing atomic radius
C. increasing electron affinity
B. decreasing electronegativity
D. decreasing ionization energy
2. Fill in the following table:
Element
F
metal or nonmetal
family
Cl
Ca
K
Cu
O
Ne
3. Of the metals in #2 which is least reactive?
Which is most reactive?
4. Of the nonmetals is #2 which is least reactive?
Which is most reactive?
5. Which is the largest Si, Si4+ or Si4- ? Why?
Answers:
1. A. C S Mg Ba
B. S C Mg Ba C. Ba Mg C S D. S C Mg Ba
2. Element
metal or nonmetal
family
F
NM
halogens
Cl
NM
halogens
Ca
M
alkaline earth
K
M
alkali
Cu
M
transition
O
NM
chalcogen
Ne
NM
noble gas
1. Most reactive metal: K least reactive: Cu
2. Most reactive nonmetal: F least reactive nonmetal: Ne
3. Largest Si4- , because it has gained 4 electrons
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Periodic Trends in Group 2 Elements
Introduction:
When the elements are arranged in order of increasing number, there is a periodic recurrence of properties that leads to
grouping of elements in the periodic table. Elements in vertical columns form groups or families that are characterized by marked
similarities in physical and chemical properties. These similarities are due, in large part, to the fact that all the elements within a group
have the same outer energy level electron configuration. The properties of density and solubility of compounds, for example, are
known to vary regularly within groups of elements.
Purpose:
To investigate the periodic variation of solubility of compounds within one group of elements
Procedure:
1. Obtain a transparency from the teacher and make sure it is wiped clean.
2. Locate one of the trays containing the dropper bottles.
3. Place one drop of the 4 metal ion solutions (Mg2+, Ca2+, Sr2+, and Ba2+) onto each of the corresponding circles of the transparency.
Do not attempt to move the transparency once the solutions have been applied.
4. Place a drop of the sulfate ion solution, SO42-, into each of the 4 circles on the left as labeled. Record your observations – write an
“S” on your lab sheet for soluble if no reaction occurs (nothing happens). Write an “I” for insoluble if a precipitate forms,
indicating that a chemical reaction occurred.
5. Repeat step 4 but use carbonate ion solution, CO32-, in each of the next 4 circles instead of the sulfate. Record your observations.
6. Repeat step 4 but use chromate ion solution, CrO42-, in the last set of 4 circles containing metal ion solutions. Record your
observations.
7. Clean and dry your transparency. Make sure all of the spots of precipitate are removed.
Analysis Questions:
1. Circle the correct word. The solubility of group 2 elements ( increases decreases ) as you go down the group.
2. Write the short-hand versions of the electron configurations for the group 2 elements used in this lab.
Mg
[Ne] 3s2
Ca
Sr
Ba
3. Write the short hand version of the electron configurations for the group 2 ions used in this lab.
Mg2+
[Ne]
Ca2+
Sr2+
Ba2+
4. Considering the above configurations of group 2 ions in question 3, why do you think group 2 elements form 2+ ions?
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Periodic Trends Solubility Lab
Data: Write an “S” for soluble if no precipitate forms. Write an “I” for insoluble if a precipitate does form. (A cloudy solution
indicates a precipitate.)
Mg2+ + SO42-
Mg2+ + CO32-
Mg2+ + CrO42-
Ca2+ + SO42-
Ca2+ + CO32-
Ca2+ + CrO42-
Sr2+ + SO42-
Sr2+ + CO32-
Sr2+ + CrO42-
Ba2+ + SO42-
Ba2+ + CO32-
Ba2+ + CrO42-
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Problem Set Unit 4
1. In an experiment each student needs to weigh out 1.84 g of Copper (Cu) wire. If we only have a spool of wire that
weighs 50.0 g, how many students can do the experiment?
2. What property did Mendeleev use to organize his periodic table?
3. Which of these sets of elements have similar physical and chemical properties?
a. oxygen, nitrogen, carbon, boron
b. strontium, magnesium, calcium, beryllium
c. nitrogen, neon, nickel, niobium
4. Give 3 properties of metals.



5. Give 3 properties of nonmetals.



6. Give 3 properties of metalloids.



7. What is so special about the noble gases?
8. Given: C Mg S Ba place these elements in order of:
a. increasing atomic radius
b. increasing electron affinity
c.
decreasing electronegativity
d. decreasing ionization energy
9. Fill in the following table:
Element
F
Cl
Ca
Cu
O
Ne
Metal or Non-Metal
Family
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10. Show the Lewis Dot Diagram for the following elements:
a.
F
b.
Ne
c.
Ca
d.
P
e.
Al
11. Group 17 elements, the halogens, are the most reactive of the nonmetal elements. Explain why this is so. Be specific.
12. How would you prove that an alloy is a mixture, not a compound? Be specific and remember your trends.