6.3. Trends in the Periodic Table http://www.ck12.org
FIGURE 6.16
The electronegativity scale was developed by Nobel Prize winning American chemist Linus Pauling. The largest
electronegativity (3.98) is assigned to fluorine, and all other electronegativity measurements are made relative to
that value.Metals and Nonmetals
Physical Properties
Elements can be classified in a number of different ways. Classifying by period and/or group is useful because it
is based on electron configuration. Another way is to classify elements based on physical properties. Three broad
classes of elements that are categorized in this way include metals, nonmetals, and metalloids.
Ametalis an element that is a good conductor of heat and electricity. Metals are also malleable, which means
that they can be hammered into very thin sheets without breaking, and ductile, which means that they can be drawn
into wires. When a fresh surface of any metal is exposed, it will be very shiny, because it reflects light well. This
property is referred to as luster. All metals are solid at room temperature except mercury (Hg), which is a liquid. The
melting points of different metals vary widely. Mercury has the lowest melting point of all pure metals (−39°C),
and tungsten (W) has the highest (3422°C). On the periodic table inFigure6.16, the metals are shaded blue and are
located to the left of the bold stair-step line. About 80 percent of the elements are metals (see examples inFigure
6.17).
Properties of Metals
- shiny ’metallic’ appearance
- solids at room temperature (except mercury)
- high melting points
- high densities