Transcript Friday 10/17 Chapter 6.1

6.1 Bonding
Two Types of Bonding
• Ionic Bonding
• Covalent Bonding
Covalent Bonding
• Sharing of electrons between 2 or more nonmetals
– Forms: Molecular Compounds
Memorize the 7 Diatomic elements shown
on page 138 of your text book!!!!
What are Ions? charged atoms that
have gained or lost electrons
Ionic Bonding
• Form between ions
• Metal + Non-metal
2 types of Ions:
• Cations: positively
charged ions, have lost
electrons (metals)
• Anions: Negatively
charged ions, have
gained electrons (nonmetals)
• Ions attract one another by electrostatic
forces.
– Opposite charges attract
6.2 Representing Chemical
Compounds
Chemical Formulas
• Molecular Formula: shows the number of
each atom present in a molecular compound
NH3
• Formula Unit: representation of ionic
compounds in lowest whole number ratios
NaCl
Law of Definite Proportions
• The masses of the elements in a compound
are always in the same proportions.
Law of Multiple Proportions
• Whenever two elements form more than one
compound, the different masses of one
element that combine with the same mass of
the other element are in ratios of small whole
numbers
Journal
• How are ions formed???
• What is the difference between cations and
anions???
6.3 Ionic Charges
Naming Rules for Monatomic Ions: ions of a single atom
Cations (positive charged metals )
Name of element + ion
Example: Na+ Sodium ion
Practice: Ca2+ _______ ____
Anions (negative charged non-metals)
Name changes ending to –ide
Example: F- Fluorine → Fluoride
Practice: S2- ______________
How do you figure out the charge
for an ion????
USING THE PERIODIC TABLE!!!
• Group 1: loose 1 electron to become cations
with a 1+ charge (Example: Na+)
• Group 2: loose 2 electrons to become cations
with a 2+ charge (Example: Sr2+)
• Aluminum (Group 3a): looses 3 electrons
Al 3+
Group 4 typically
do not form ions.
• Group 7A: gains 1 electron
become anions with a 1- charge
• Group 6a: gains 2 electrons
become anions with a 2- charge
• Group 5a: gains 3 electrons
become anions with a 3- charge
Journal:
Write the formula and the name for the ions
formed by the elements:
Cl
S
K
Ca
Journal:
Write the formula and the name for the ions
formed by the elements:
Cl
S
K
Ca
ClS2K+
Ca2+
Chloride
Sulfide
Potassium Ion
Calcium Ion
Transition Metals may form
several different ions
You are responsible for knowing that the roman
numeral indicates the charge of the given ion.
Roman Numerals You should know:
I=1
II = 2
III = 3
IV = 4
V=5
VI = 6
VII = 7
VIII = 8
IX = 9
X = 10
Example:
You should know that:
• Chromium (II) indicates a Chromium ion with
a charge of 2+, Cr2+
Journal: What is the charge and formula for….
Copper I
Copper II
Lead IV
Example:
You should know that:
• Chromium II indicates a Chromium ion with a
charge of 2+, Cr2+
Journal: What is the charge and formula for….
Copper I : Cu+
Copper II : Cu2+
Lead IV: Pb4+
Polyatomic Ions
• Ions with more than 1 atom
Examples:
OH- hydroxide
NH4+ ammonium
NO2 – Nitrite
SO3 2– Sulfite
NO3 – Nitrate
SO4 2– Sulfate
Memorize the name and charge of the
polyatomic ions found on page 147 of the
textbook!!!!
Practice