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Chemistry - Unit 4: Chapters 5-6 Periodic Table and Characteristics of Elements
Vocab Quiz: Wed. March 5
EQs/PS Due: Monday, 3/10
Element Trading Cards Project: Friday, March 7
Test Date: Monday, 3/10
Vocabulary:
average atomic mass
metal
Mendeleev
ionization energy
alkali metals
actinides
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:
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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:
Review:
1. 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.
New Material:
2. Copy and fill in the following table:
Element/ion
Fe
K+
# of protons
# of neutrons
# of electrons
27
25
O2Strontium-89
3. List the family for each of the following:
A. Sr
B. Ar
C. Cl
D. K
E. O
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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)
5. 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?
6. 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
7. Write the Lewis Dot Diagram for phosphorus and barium
Problem set – on the back page – Review material – start early!
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?
5. Define a group/family.
6. Indicate where the following are located on the periodic table.
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metals
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non-metals
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metalloids
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!)
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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:
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.
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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
F
Cl
Horizontal Trend (period trend – remember same period = same # of energy levels)
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.
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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
With partner: Put the following in order of increasing IE
Na
Te
S
Li
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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
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
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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?
VI.
Ca or Ca2+
N or N3-
Al3+ or Al
C4- or C or C4+
Reactivity:
Metals: most reactive ___________ and _______________
Nonmetals more reactive ____________ and _______________ (Except Noble gases- Why?)
Practice:
Circle the most reactive metal:
Circle the most reactive nonmetal:
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
Se
Au
Cs
Sr
Ti
Cl
O
Ne
P
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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
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
D. S C Mg Ba
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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.
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5. Give 3 properties of nonmetals.
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6. Give 3 properties of metalloids.
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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
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9. Fill in the following table:
Element
Metal or Non-Metal
F
Cl
Ca
Cu
O
Ne
10. Show the Lewis Dot Diagram for the following elements:
a. F
b. Ne
c. Ca
d. P
e. Al
Family