Chemistry Review
Part 2: Atomic Structure and Periodic Relationships
1. Parts of the Periodic Table
2. Introduction to the SOL Periodic Table
3. Atomic Structure and the Periodic Table
4. Periodic Trends in Atomic Radius, Ionization Energy, and
Electronegativity.
5. Isotopes and Average Atomic Mass
6. Historical and Quantum Models of the Atom
A calculator will be helpful, but not necessary for this powerpoint.
The columns are called groups or families. Groups have similar physical and
chemical properties and the same number of valence electrons
Name the groups boxed in yellow, orange, green and blue.
Name the groups boxed in yellow, orange, green and blue. Alkali metals, Alkaline
Earth metals, Halogens, and Noble or Inert Gases.
The rows are called periods. The period number matches the principle energy level
of the element. This will be the principle energy level of the valence electrons.
What is the principle energy level of Nickel, Ni?
What is the principle energy level of Nickel, Ni? 4—it is in the row numbered 4
Chemistry Review—Atomic Structure
Using the Periodic Table
Keep this Adobe file open as you work on the review
Let’s use the periodic table to answer some questions about
Silicon
Chemistry Review—Atomic Structure
Using the Periodic Table
Let’s use the periodic table to answer some questions about Silicon.
How many protons does Silicon have?
Chemistry Review—Atomic Structure
Using the Periodic Table
Let’s use the periodic table to answer some questions about Silicon.
How many protons does Silicon have? 14 protons = atomic number.
How many electrons does neutral Silicon have?
Chemistry Review—Atomic Structure
Using the Periodic Table
Let’s use the periodic table to answer some questions about Silicon.
How many protons does Silicon have? 14 protons = atomic number.
How many electrons does neutral Silicon have? 14 electrons (#
electrons = # protons in neutral atoms)
How many neutrons does Silicon-30 have?
Chemistry Review—Atomic Structure
Using the Periodic Table
Let’s use the periodic table to answer some questions about Silicon.
How many protons does Silicon have? 14 protons = atomic number.
How many electrons does neutral Silicon have? 14 electrons (#
electrons = # protons in neutral atoms)
How many neutrons does Silicon-30 have? 16 neutrons. Silicon-30 is
an isotope of Silicon. It has a mass number of 30. The mass number is
protons + neutrons.
Chemistry Review—Atomic Structure
Using the Periodic Table
Let’s use the periodic table to answer some questions about Silicon.
How many protons does Silicon have? 14 protons = atomic number.
How many electrons does neutral Silicon have? 14 electrons (#
electrons = # protons in neutral atoms)
How many neutrons does Silicon-30 have? 16 neutrons. Silicon-30 is
an isotope of Silicon. It has a mass number of 30. The mass number is
protons + neutrons.
What is the molar mass of Silicon?
Chemistry Review—Atomic Structure
Using the Periodic Table
Let’s use the periodic table to answer some questions about Silicon.
How many protons does Silicon have? 14 protons = atomic number.
How many electrons does neutral Silicon have? 14 electrons (#
electrons = # protons in neutral atoms)
How many neutrons does Silicon-30 have? 30 neutrons. Silicon-30 is
an isotope of Silicon. It has a mass number of 30. The mass number is
protons + neutrons.
What is the molar mass of Silicon? 28.0855 grams/mole (this is the
same as the atomic mass on the periodic table)
Chemistry Review—Atomic Structure
Using the Periodic Table
Let’s use the periodic table to answer some questions about Silicon.
How many protons does Silicon have? 14 protons = atomic number.
How many electrons does neutral Silicon have? 14 electrons (#
electrons = # protons in neutral atoms)
How many neutrons does Silicon-30 have? 30 neutrons. Silicon-30 is
an isotope of Silicon. It has a mass number of 30. The mass number is
protons + neutrons.
What is the molar mass of Silicon? 28.0855 grams/mole (this is the
same as the atomic mass on the periodic table)
How many valence electrons does Silicon have?
Chemistry Review—Atomic Structure
Using the Periodic Table
Let’s use the periodic table to answer some questions about Silicon.
How many protons does Silicon have? 14 protons = atomic number.
How many electrons does neutral Silicon have? 14 electrons (#
electrons = # protons in neutral atoms)
How many neutrons does Silicon-30 have? 30 neutrons. Silicon-30 is
an isotope of Silicon. It has a mass number of 30. The mass number is
protons + neutrons.
What is the molar mass of Silicon? 28.0855 grams/mole (this is the
same as the atomic mass on the periodic table)
How many valence electrons does Silicon have? 4 valence electrons.
Look for electrons in the highest principle energy level.
Chemistry Review—Atomic Structure
An s orbital holds 2
electrons w/ opposite spins
Chemistry Review—Atomic Structure
Each p orbital holds 2ewith opposite spins
Chemistry Review—Atomic Structure
Each d orbital holds 2ewith opposite spins
Chemistry Review—Atomic Structure
The orbitals and the periodic table
The s
suborbital fills
Chemistry Review—Atomic Structure
The orbitals and the periodic table
The p
suborbitals fill
Chemistry Review—Atomic Structure
The orbitals and the periodic table
The d
suborbitals fill
Chemistry Review—Atomic Structure
Valence electron configuration and the periodic table
All group 13 elements have the
valance electron configuration
ns2np1.and 3 valence electrons
Chemistry Review—Atomic Structure
Valence electron configuration and the periodic table
All group 15 elements have the
valance electron configuration
ns2np3.and 5 valance electrons.
Chemistry Review—Atomic Structure
Valence electron configuration and the periodic table
What is the valence configuration
of the halogens?
Chemistry Review—Atomic Structure
Valence electron configuration and the periodic table
What is the valence configuration
of the halogens? ns2np5.
Chemistry Review—Atomic Structure
Periodic Trends in Atomic Radius, Ionization Energy, and Electronegativity.
Atomic Radius: the radius of an atom in picometers
First Ionization Energy: The energy needed to remove the first
valence electron from a gaseous atom.
Electronegativity: The tendency of an atom to attract electrons to
itself when chemically combined with another element.
Chemistry Review—Atomic Structure
Periodic Trends in Atomic Radius, Ionization Energy, and Electronegativity.
Atomic Radius: the radius of an atom in picometers
1
2
13
14
15
16
17
18
Chemistry Review—Atomic Structure
Periodic Trends in Atomic Radius, Ionization Energy, and Electronegativity.
First Ionization Energy: The energy needed to remove the first
valence electron from a gaseous atom.
Ionization energy
increases as you
move to higher
number groups.
Group 18 has the
highest 1st ionization
energy.
Ionization energy
decreases as you
move down the
periodic table.
Chemistry Review—Atomic Structure
Periodic Trends in Atomic Radius, Ionization Energy, and Electronegativity.
First Ionization Energy: The energy needed to remove the first
valence electron from a gaseous atom.
Chemistry Review—Atomic Structure
Periodic Trends in Atomic Radius, Ionization Energy, and Electronegativity.
Electronegativity: The tendency of an atom to attract electrons to
itself when chemically combined with another element.
The halogen group has the highest electronegativity of the families. The first
period has the highest electronegativity. Noble gases do not have
electronegativity as the valence shell is already full.
Chemistry Review—Atomic Structure
Anions, Cations, and Electron Configuration
Cations form by losing valance electrons to take on a noble gas configuration
(ns2np6)
Chemistry Review—Atomic Structure
Anions, Cations, and Electron Configuration
Cations form by losing valance electrons to take on a noble gas configuration
(ns2np6)
So Li loses the 2s1 electron to form Li+1.
Mg loses both 3s2 electrons to form Mg+2
Al loses three electrons from 3s23p1 to form Al+3
Chemistry Review—Atomic Structure
Anions, Cations, and Electron Configuration
Anions form by gaining valance electrons to take on a noble gas configuration
(ns2np6)
So F becomes F1- by gaining a 2p electron to have the new valance
configuration 2s22p6.
S becomes S2- by gaining two 2p electrons to have the new valance
configuration 3s23p6.
N becomes N3- by gaining three 2p electrons to have the new valance
configuration 2s22p6.
Chemistry Review—Atomic Structure
Isotopes: elements with the same number of protons, but a different number
of neutrons.
12
C
6
13
C
6
Carbon-14 has ___ protons and ___ neutrons
14
C
6
Chemistry Review—Atomic Structure
Isotopes: elements with the same number of protons, but a different number
of neutrons.
12
C
6
13
C
6
Carbon-14 has 6 protons and 8 neutrons
14
C
6
Chemistry Review—Atomic Structure
Isotopes: elements with the same number of protons, but a different number
of neutrons.
12
C
6
13
C
6
14
C
6
You figure out the average atomic mass of a compound by using a
weighted average of the mass number for each isotope.
Example: a sample contains 10% C-13, 60% C-12 and 40% C-14. The
average atomic mass is
(0.10 x 13) + (0.60 x 12) + (0.30 x 14) = 12.7
A. Octet Rule
• Remember…
– Most atoms form bonds in order to have 8
valence electrons.
C. Johannesson
A. Octet Rule
• Exceptions:
F
F
 Hydrogen  2 valence e
F
B
F
 Groups F
1,2,3 get
2,4,6
valence e
S
F
H
N
O
O
H
 Expanded octet

more
than
8
F
Very
unstable!!
valence
e
(e.g.
S,
P,
Xe)
F
F
-
-
-
 Radicals  odd # of valence eC. Johannesson
Molecules are polar if there is uneven distribution of electrons or
Atoms.
O-O
H-O-H
is nonpolar
is polar
Even distribution
Uneven distribution
Chemistry Review—Atomic Structure
References
www.markrosengarten.com NY Regent’s Exam Powerpoint