http://www.ck12.org Chapter 8. Ionic and Metallic Bonding
8.3 Metals and Metallic Bonds http://www.ck12.org Contents
Lesson Objectives
- Describe the general properties of metals compared to other element types.
- Describe the arrangement of atoms in metallic substances.
- Describe the behavior of electrons in metals.
- Define and give examples of alloys.
Lesson Vocabulary
- malleable: When pure metals are able to be stamped, pressed, or rolled into thin sheets.
- ductile: Metal that can be stretched, bent, or twisted without breaking.
- toughness: The ability of a material to withstand shock and to be deformed without rupturing.
- luster: When pure metals tend to be shiny in appearance.
- corrosion: The gradual degradation of a material due to its exposure to the environment.
- metallic bond: The attraction of the stationary metal cations to the surrounding mobile electrons.
- alloy: A mixture of pure metals.
- amalgam: An alloy that is mostly composed of mercury.
Check Your Understanding
- Identify the ions that make up the following compounds:
a. NaCl
b. BaSO 4
c. K 2 O - How many valence electrons do the neutral atoms of metals in Groups 1, 2, and 3 in the periodic table have?
Introduction
Metals represent approximately 25% of the elemental makeup of the Earth’s crust. The bulk of these metals,
primarily aluminum, iron, calcium, sodium, potassium, and magnesium, are typically found in combined form.
The most abundant metal is aluminum, which occurs almost exclusively as the ionic mineral bauxite. The other
most common metals, including iron, sodium, potassium, magnesium, and calcium, are also found primarily as the
cationic portion of an ionic compound. Very few metals actually occur naturally as pure substances. The ones that
do are often referred to as precious or semi-precious metals.
As pure substances, metals are tough, yet malleable. They are strong, and some of them are quite resistant to
corrosion. They are also good conductors of electricity and heat. Due to these and other useful properties, pure