Post on 03-Jan-2016
Ch 7 Ions and metallic bonding
Ionic Bonding – electrical attraction between large numbers of cations and anions (metals & nonmetals); forms solid crystals
Octet rule: Atoms tend to achieve a noble gas electron configuration when forming a chemical bond. (oct = 8; s & p orbitals add to 8; ns2p6)
Use electron dots to predict the formulas for the compound formed between
a) Li and Br b) Na and S
see pg. 203
Cation anion formula name
Writing formulas & names
1) Crystalline solids at room temperature *denoted by letter (c) ; 3D crystalline
network; where each cation is surrounded by anions
2) HIGH MELTING POINTS!ex/ NaCl melts at 800 oC (1,474 oF)
3) Conduct electricity if dissolved in water (ions separate) & when in a molten state.
3 properties of ionic compounds
Get a clicker for review
The chlorine atom gains seven electrons when it becomes an ion.
True or False?
What is the formula for sodium chloride?A) NaClB) ClNaC) Na7Cl1D) SCl
What is the formula for zinc nitride? Zn2+ N3-
A) ZnN B) Zn2N C) Zn3N2
D) ZnN2 E) Zn2N3 F) ZnN3
What is the name given to the electrons in the highest occupied energy level?
A) AnionsB) CationsC) Valence electronsD) Orbital electrons
What is the typical charge of group 2?
A) Negative twoB) Positive twoC) IDKD) Positive one
How many valence electrons does oxygen have?
A) NoneB) OneC) SixD) eight
True or False
A cation is positively charged because it will gain electrons to have a stable electron configuration like a noble gas.
True or False
The name of PbO is lead(II) oxide
Yes or No The charge of an anion is negative.
Please make your selection When an aluminum atom loses its valence electrons, what is the charge on the resulting ion?
a. 2+ b. 3+ c. 2– d. 1+
Please make your selection
The electron configuration of a fluoride ion, F–, is
a. 1s2 2s2 2p5. b. the same as that of the neon atom.
c. 1s2 2s2 2p6 3s1. d. the same as that of a potassium ion.
What is the formula for iron(II) oxide? A) Fe2O3
B) Fe2O2
C) FeOD) Fe3O2
Please make your selection
An ionic compound is
a. electrically neutral.b. composed of anions and cations.
c. held together by ionic bondsd. all of the above
Please make your selection
Which element when combined with chlorine would most likely form an ionic compound?
a. lithiumb. phosphorusc. oxygend. bromine
What is the formula for cobalt(II) nitrate? A) Co3N2 B) Co(NO3)2 C) Co(NO3)3
Metallic BondsMetallic bonding - between metal atoms;
valence electrons are shared equally in a “sea of electrons”
*This explains the properties of metals!
The valence electrons are mobile and can drift freely from one part of the metal to another.
Electrons are delocalized & gives metals Multidirectional strength (stretching & sheets)
Look at page 209
When a metal is subjected to pressure, the metal cations easily slide past one another (hence malleable & ductile)
• If an ionic crystal is struck with a hammer, the blow tends to push the positive ions close together.
• The positive ions repel one another, and the crystal shatters (brittle).
Sea of electrons
Metal cation
Force Force
Metal cation
Strong
repulsions
Nonmetal anion
Metal Ionic crystal
Which of the following models can describe the valence electrons of metals?
A. A body-centered cube
B. Octets of electrons
C. A rigid array of electrons
D. A sea of electrons