unit 5: ionic bonding & nomenclature. section 1: ions pyrite (fes 2 ) is a common mineral that...
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Unit 5: Ionic Bonding & Nomenclature
Section 1: Ions
Pyrite (FeS2) is a common mineral that is often mistaken for gold—hence its nickname, “fool’s gold.” Pyrite is an example of a crystalline solid. In this chapter, you will learn about crystalline solids composed of ions that are bonded together. But first you need to understand how ions form from neutral atoms.
Valence Electrons:electrons in the highest
occupied energy level
- determines chemical properties
- only e- involved in chemical reactions
9-Fluorine (F) 11-Sodium (Na)10-Neon (Ne)
Group # =
Valence #
Electron dot structures:diagrams showing valence e- as dots
Electron dot structures:diagrams showing valence e- as dots
Electron dot structures:diagrams showing valence e- as dots
Electron dot structures:diagrams showing valence e- as dots
Electron dot structures:diagrams showing valence e- as dots
Electron dot structures:diagrams showing valence e- as dots
Electron dot structures:diagrams showing valence e- as dots
Electron dot structures:diagrams showing valence e- as dots
Electron dot structures:diagrams showing valence e- as dots
The Octet Rule• most atoms form bonds to have
8 valence e-
• full outer energy level
• like the Noble Gases
Ne
Lewis dot structure
nonmetals gain electrons to form negative ionsto achieve a complete octet in its valence level.
Anions
metals lose electrons to form positive ionsleaving a complete octet in the next-lowest energy level.
Cations
The electron configuration of the sodium ion is the same as that of a neon atom.
Group 1 always 1+ charge
7.1
MgNa
Mg2+Na+
Group 2always 2+ charge
1+
2+ 3+
Ionic Compounds
Charges of Ions
Formation of Anions7.1
The electron configuration of the chloride ion is the same as that of argon.
Formation of Anions
Oxygen is in Group 6A.
7.1
7.1
Group 16 (6A) always 2- charge
Group 15 (5A) always 3- charge
Group 17 (7A) always 1- charge
F F
O O
N N
-
2-
3-
7.1Anions names typically end in -ide
1+
2+ 3+ 3- 2- 1-
0
charges vary but always +
Charges of Ions
Conceptual Problem 7.1
7.1
Fill in the blanks.
1.Iodine gains __ e- to form ___
2.Magnesium loses __ e- to form ___
3.Sulfur _____ __ e- to form ___
4.Aluminum _____ __ e- to form ___
1 I-
2 Mg2+
gains 2 S2-
loses 3 Al3+
Quick Quiz!
1. How many valence electrons are in an atom of oxygen?
A. 2
B. 4
C. 6
D. 8
Quick Quiz.
2. Atoms that tend to gain a noble gas electron configuration by losing valence electrons are
A. metals.
B. nonmetals.
C. halogens.
D. anions.
3. When a magnesium atom forms a cation, it does so by
A. losing two electrons.
B. gaining two electrons.
C. losing one electron.
D. gaining one electron.
Quick Quiz.
Quick Quiz.
4. When a bromine atom forms an anion, it does so by
A. losing two electrons.
B. gaining two electrons.
C. losing one electron.
D. gaining one electron
Quick Quiz.
5. Write the name and the symbol of the ion formed from a nitrogen atom.
A. nitrogen ion, N3+
B. nitride, N-
C. nitride, N3-
D. nitrogen ion, N2-