Chapter 7 Ionic and Metallic Bonding
How many electrons will each calcium gain or lose in forming an ion?
+2
How many electrons will aluminum gain or lose in forming an ion?
+3
How many electrons will fluorine gain or lose in forming an ion?
-1
How may electrons will oxygen gain and lose in forming an ion?
-2
How many valence electrons are in potassium?
1
Identify the number of valence electrons in a magnesium atom.
2
How many valence electrons are in magnesium?
2 valence electrons
Identify the number of valence electrons in a carbon atom.
4
How many valence electrons are in carbon?
4 valence electrons
How many valence electrons are in oxygen?
6
Ionic compound
A compound composed of positive and negative ions
Alloy
A mixture composed of two or more element, at least one of is a metal
How are anions formed?
A negatively charged ion is produced when an atom gains one or more valence electrons.
Electron dot Structure
A notation that depicts valence electrons as dots around the atomic symbol of the element; the symbol represents the inner electrons and atomic nucleus; also called Lewis dot structure
How are cations formed?
A positively charged ion is produced when an atom loses one or more valence electrons.
Write the correct chemical formula for the compounds formed from aluminum and nitrogen?
AlN
What is the electrical charge of an ionic compound?
Although they are composed of ions, ionic compounds are electrically neutral.
Valence Electrons
An electron in the highest occupied energy level of an atom
Chemical formula
An expression that indicates the number and type of atoms present in the smallest representative unit of a substance
Describe how the sea-of-electrons model is used to explain the physical properties of metals.
Atoms form positive ions by losing valence electrons and form negative ions by gaining valence electrons. The electrostatic forces between the oppositely charged ions hold the cations and anions together in an ionic compound. Ionic compounds generally have high melting points and can conduct an electric current in a solution and in the molten state. Metals are made up of closely packed cations surrounded by a sea of electrons. the sea-of-electrons model explains why metals are good conductors of electric current and why they are ductile and malleable.
Atoms of which elements tend to gain electrons? Atoms of which elements tend to lose electrons?
Atoms of metals tend to lose their electrons, and atoms of non-metals tend to gain electrons.
Octet rule
Atoms react by gaining or losing electrons so as to acquire the stable electron structure of a noble gas, usually eight valence electrons.
Write the formula for barium chloride
BaCl2
Write the correct chemical formula for the compounds formed from calcium and oxygen?
C2O
Write the formula for calcium fluoride
CaF2
What is meant by the terms ductile and malleable?
Ductile: to be drawn out into a thin wire Malleable: to be able to be hammered without it breaking
Why do ionic compounds conduct electric current when they are melted or dissolved in water?
Electric current is the flow of charged particles. When ionic crystals dissolve in water the ions broken apart this allows them to be able to move freely about in the solution
"body-centered cubic structure
Every Aton has eight neighbors (except those on the surface)
"face-centered cubic arrangement
Every atom has twelve neighbors
Hexagonal close-pack arrangement
Every atom has twelve neighbors ( has a different pattern than face-centered cubic structure)
Identify the charge of the ion formed when a fluorine atom gains one electron
F-
Identify the ion formed when a potassium atom loses one electron
K+
Write the correct chemical formula for the compounds formed from potassium and sulfur?
K2S
Which of the following statements about the formation of a lithium ion is true?
Li loses one electron to form Li+
Write the formula for lithium oxide
Li2O
Why is it possible to bend metals but not ionic crystals?
Metals have metallic bonds and nuclei are in a sea of electrons where ionic crystals are in lattice form that is hard to move.
Write the formula for magnesium oxide
MgO
What are three properties of ionic compounds?
Most ionic compounds are crystalline solids at room temperature, ionic compounds generally have high melting points, and ionic compounds can conduct an electric current when melted or dissolved in water.
Which ions do the electron configuration 1s^2 2s^2 2p^6
N^3-, Mg^2+
Write the correct chemical formula for the compounds formed from sodium and oxygen?
Na2O
Which of the following properties can you determine about a representative element if you know the elements group number on the periodic table?
Number of valence electrons
Which of the following statements about the formation of the sulfide ion is true?
S gains two electrons to form S2-
Name two widely used alloys and describe some of their uses.
Sterling silver is harder and more durable than pure silver, but soft enough to be made into jewelry and tableware. Bronze is harder than copper and is easier to cast into molds.
Ionic bond
The electrostatic attraction that binds oppositely charged ions together
Metallic bonds
The forces of attraction between the free floating valence electrons and the positively charged metal ion
How can you describe the arrangement of sodium ions and chloride ions in a crystal of sodium chloride?
The ions in solid sodium chloride are arranged in an orderly pattern.
Formula unit
The lowest whole-number ratio of ions in an ionic compound; in magnesium chloride, the ratio of magnesium ions to chloride ions is 1:2 and the formula unit is MgCl2
Coordination number
The number of ions of opposite charge that surround each ion in a crystal
What properties characterize ionic compounds?
They are crystalline solids at room temperature, and they are generally have high melting points, they can conduct an electric when melted or dissolved in water.
How is the arrangement of fruit in a stack of oranges similar to the way some metal atoms are arranged in metallic crystals?
They have closed-packed arrangement which helps save space while allowing as many oranges as possible to be stacked up high.
"Why are alloys important? "
"Alloys are important because their properties are often superior to those of their component elements"
"How can you model the valence electrons of metal atoms?
"The valence electrons of atoms in a pure metal can be modeled as a sea of electrons. "
How do you find the number of valence electrons in an atom of representative elements?
To find the number of valence electrons in an atom of a representative element, simply look at its group number.
Identify the charge of the ion formed when a zinc atom loses two electrons
Zn2+
Halide ions
a negative ion formed when a halogen atom gains an electron
