Chapter 6 The Periodic Table and Periodic Law

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Periodic Table: Bell Ringer

What does a period and a group refer to on
the periodic table?

What period and group is Bromine on?

What element is on period 5 and group 10?

For homework, how did you classify the
elements on the periodic table?
Periodic Table
Metallic Properties
Non-metallic Properties
History of the Periodic Table
Dmitri Mendeleev:
• Russian chemists and teacher
•When organized elements into groups
by similar chemical properties,
he observed the periods increasing in
atomic mass.
• His organization system was
successful at predicting undiscovered
elements.
•Do you observe any inconsistencies
with his organization system?
History of Periodic Table
Henry Moseley:
•British Physicists
•Observed that when elements were
placed in groups by chemical properties,
the periods consistently increased by
atomic number.
•Currently accepted organization system
for elements.
Bell Ringer: Periodic Table
1. How is the current periodic table arranged?
2. Classify the following properties as metallic or nonmetallic.
a. ductile b. low density c. high luster d. insulator
3. What element is on period 3; group 16?
4. Circle the elements below that have similar
chemical properties:
Carbon (C); Nitrogen (N); Silicon (Si); Boron (B)
Organization of Periodic Table

Why do elements in the same group have similar
chemical properties?
Valence Electrons
•Electrons
in the highest energy level of an element’s atom.
•Calculate
using short-hand electron configuration.
•Determines
the chemical reactivity of an element.
Periodic Table : Bell Ringer
1. a. What period and group is Aluminum on?
b. What element is in period 4; group 2 ?
2. Circle the elements below that have similar
chemical properties.
Carbon (C), Nitrogen, (N), Silicon (Si), Boron (B)
3. What are valence electrons?
4. Why is it important to know the number of
valence electrons an element can have?
Short-Hand Electron Configuration
•Short -hand configuration targets valence electrons
Ex.
Sulfur (S): [ Ne] 2s22p4 = 6 valence electrons
Valence Electrons Worksheet Key
1. 7 ve2. 5ve3. 2ve4. 5ve5. 2ve6. 8ve7. 1ve8. 2ve9. 2ve10. 6ve-
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
1ve2ve4ve7ve6ve2ve3ve1ve8ve2ve-
Organization of Periodic Table

Why do elements in the same group have similar
chemical properties?
Periodic Table Lab: Valence Electrons
Lab
grps
grp 1 grp 2
veve-
grp 3-12 grp 13
veve-
grp 14
ve-
grp 15
ve-
grp 16
ve-
grp17 grp18
veve-
A
B
C
D
What can be concluded from the data table?
Periodic Table: Valence Electrons
Lab
grps
grp 1 grp 2
veve-
grp 3-12 grp 13
veve-
grp 14
ve-
grp 15
ve-
grp 16
ve-
grp17 grp18
veve-
A
1
2
2
3
4
5
6
7
8
B
1
2
2
3
4
5
6
7
2
C
1
2
2
3
4
5
6
7
8
D
1
2
2
3
4
5
6
7
8
What can be concluded from the data table?
Common Periodic Table Groups
Periodic Groups
Group #
Alkali Metals
Valence
Electrons
1 ve-
• Highly Reactive metals
• Only needs to lose 1 ve- to reach
STABILITY. Depends on lower energy
level that is filled.
2ve-
•Reactive
•Only needs to lose 2 ve- to reach
STABILITY.
•Depends on lower energy level that is
filled.
1
Alkaline-Earth
Metals
2
Transitional
Metals
2ve-
3-12
Halogens
17
Chemical Properties
•Reactive
•Varies in amount of valence electrons
lost to reach STABILITY.
•Depends on lower energy level that is
filled.
•Highly Reactive non-metals.
•Only needs to gain 1 ve- to reach
STABILITY.
•Depends on filling up outer energy level.
Chemical Stability
Metals:
 Will lose ve- to reach stability.
 Form cations (+ charged atoms)
Non-metals:
 Will gain ve- to reach stability.
 Form anions (- charged atoms)
Chemical Stability
Determine what type of ion each element below
would form to reach maximum stability.
a.
b.
c.
d.
e.
Sodium Na1+
Oxygen O2Argon
Ar
Phosphorus P3Chromium Cr2+
Bell Ringer: Chemical Stability
1.
Write down what comes to mind when you think
about chemical stability for elements.
2. Label your periodic table with the following groups:
Alkali metals (Group 1)
Alkaline earth metals (Group 2)
Halogens (Group 17)
Noble gases (Group 18)
Transitional metals (Group 3-12)
Periodic Table and Groups
Ions and Chemical Stability Lab
In pairs, look at 16 different elements and answer
the following questions:
a. Metal or non-metal
b. Neutral, anion, or cation.
c. Symbol and specific charge if needed.
*neutral if element is naturally stable (noble gas)
*anion: non-metal not naturally stable
*cation: metals

Size of an Ion
Use the diagram below to determine what happens
to the size of an atom when it becomes an ion.
Size of a Cation
A cation is smaller than its parent atom.
Why? Because metals will lose an energy level in the process
of becoming a cation.
Size of a Cation
Size of an Anion
Size of an Anion
A anion is larger than its parent isotope.
Why? Repulsion force increases as more electrons are
added to the outer most energy level. Swells the energy leve
Size of an Anion
Size of Ions
a.
Circle the atom that is larger in size.
Ca or Ca2+
b.
S or S2-
1.
Circle the atom that is smaller in size.
a. Al or Al3+
2.
b. N or N 3-
Bell Ringer: Chemical Stability
1.
a. Most stable group on periodic table? Explain.
b. Most reactive metallic group? Explain.
c. Most reactive non-metallic group? Explain.
2. Predict what type of ion each element below would
form to reach maximum stability.
a. Cesium
b. Selenium
c. Helium
3. Identify which atom is larger in each example below.
a. Al or Al3+
b. Br or Br 1-
Periodic Trends
Periodic Properties and Trends
Atomic Radius:
-Size of an atom.
- Distance from nucleus to highest energy level for
that atom. (picometers, pm).


-
Ionization Energy:
Energy required to remove an electron from an
atom.
Energy required to form a cation.
Periodic Trends: Atomic Radius
Atomic Number vs. Atomic Radius
200
atomic raidus (pm)
180
160
140
120
100
80
60
40
20
0
1
2
3
4
5
6
7
8
9
10
11
12
atomic number
13
14
15
16
17
18
Periodic Trends: Atomic Radius
Across a Period
Atomic Number vs.
Atomic Radius
200
atomic raidus (pm)
180
160
140
120
100
80
Down a Group
60
40
20
0
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16 17 18
atomic number
Periodic Trends: Ionization Energy
Atomic Number vs. Ionization Energy
Ionization Energy (kJ/mol)
2500
2000
1500
1000
500
0
1
3
5
7
9
11
13
Atomic Number
15
17
Periodic Trends: Ionization Energy
Atomic Number vs. Ionization Energy
2500
Ionization Energy (kJ/mol)
Across a Period:
2000
1500
1000
Down a Group:
500
0
1
3
5
7
9
11
Atomic Number
13
15
17
Exit Slip
1 Use your graph on atomic radius and ionization
energy answer these questions:
a. Rank the following elements from largest to
smallest in size. Explain your results.
Ar, Mg, S Al
b. Rank the following elements from smallest to
largest in ionization energy. Explain your results.
Ne, Ar, He
Periodic Table
Representative Elements: tall groups .
•Transitional Elements: short groups.
•
Hydrogen Lab
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