http://www.ck12.org Chapter 2. Matter
Properties of Metals
Elements in the same class share certain basic similarities. In addition to conducting electricity, many metals have
several other shared properties, including those listed below. You can dig deeper into the properties of metals at this
URL: http://www.bbc.co.uk/schools/gcsebitesize/science/add_gateway_pre_2011/periodictable/metalsrev1.shtml.
- Metals have relatively high melting points. This explains why all metals except for mercury are solids at room
temperature. - Most metals are good conductors of heat. That’s why metals such as iron, copper, and aluminum are used for
pots and pans. - Metals are generally shiny. This is because they reflect much of the light that strikes them. The mercury
pictured above is very shiny. - The majority of metals are ductile. This means that they can be pulled into long, thin shapes.
- Metals tend to be malleable. This means that they can be formed into thin sheets without breaking. An
example is aluminum foil, also pictured in theFigure2.93.
FIGURE 2.93
Q:The defining characteristic of metals is their ability to conduct electricity. Why do you think metals have this
property?
A:The properties of metals—as well as of elements in the other classes—depend mainly on the number and
arrangement of their electrons.
Explaining the Properties of Metals
To understand why metals can conduct electricity, consider the metal lithium as an example. An atom of lithium is
modeled below. Look at lithium’s electrons. There are two electrons at the first energy level. This energy level can
hold only two electrons, so it is full in lithium. The second energy level is another story. It can hold a maximum of
eight electrons, but in lithium it has just one. A full outer energy level is the most stable arrangement of electrons.
Lithium would need to gain seven electrons to fill its outer energy level and make it stable. It’s far easier for lithium
to give up its one electron in energy level 2, leaving it with a full outer energy level (now level 1). Electricity is a
flow of electrons. Because lithium (like most other metals) easily gives up its “extra” electron, it is a good conductor
of electricity. This tendency to give up electrons also explains other properties of metals such as lithium.