Course CHEM111E (Chemistry for Engineers)
Title of the
Module Unit III. Chemistry of Engineering Materials – Metals
Learning
Objectives
At the end of this module, the student shall be able:
a. To distinguish different types of fuels.
b. To calculate the amount of energy that can be derived from
fuels.
Content
I. Structure of Metals
II. Properties of Metals
III. Classification of Metals
Introduction
Metals, from the Greek word ‘’metallon” (mine or quarry), are used in various
aspects of our daily lives. Roughly 25% of the earth’s crust is comprised of metals
and due to this abundance and metals’ varied properties, they can be used in
construction, home appliances, tools, decorative items and jewelry, coinage and
more.
The history of refined metals is very long. The smelting and use of copper has
been show to date back to the Bronze age, at around 3500 B.C. Gold, silver,
meteoric iron, and lead have been in use earlier than that. The smelting of iron
dates back to around 1500 B.C. and subsequent developments of early forms of
steel followed at around 1200 B.C. Further discoveries of new types of metals and
the development of modern alloys from early simple steel alloys to more
complicated and specialized ones have happened over the years, to cater to
various needs and applications.
I. Structure of Metals
Almost all metallic elements are crystalline solids at room temperature.
Only cesium, gallium and mercury are not (with mercury being the only metal
that is not solid at room temp.). This means that atoms of metals and metallic
substances are arranged in an orderly and regular fashion.
Imagine the metal atoms to be identical spheres which are stacked together
in layers, each layer’s spheres slotting into the spaces between where the
spheres of the other layers come together, much like how fruits are stacked in
displays or how balls and cannonballs are stacked together.
1
