Video Transcript
Which of the following is not
considered a metal? (A) Silicon, (B) lithium, (C)
potassium, (D) sodium, (E) cesium.
Metals have very different chemical
and physical properties when compared to nonmetals. This is because the atoms of metals
and nonmetals are bonded in different ways. Metallic bonding is the strong
electrostatic attraction between positively charged metal cations and delocalized
electrons. This bonding structure is
responsible for many of the properties of metals, including that they tend to be
hard, electrically conductive, malleable, ductile, and lustrous. Metals also tend to have high
melting points, boiling points, and thermal conductivity.
Let’s take a look at where the
metals are located on the periodic table. In the figure, metals are
represented with the color pink, and they are found on the left-hand side of the
periodic table. Nonmetal elements are represented
with the color blue, and they are found on the right-hand side of the periodic
table, except for hydrogen. The metalloids are represented with
the color orange, and they can be found in between the metals and nonmetals. And finally, the elements outlined
in black are elements with unknown chemical properties.
Now, let’s have a closer look at
the metalloids to see if any of the answer choices fall into this category. We can see that silicon, or Si, is
found in the metalloid section. On the other hand, lithium,
potassium, sodium, and cesium are all metals.
Metalloids are elements that have
some properties of metals and some properties of nonmetals. Silicon fits this description well
because it has properties that are similar to metal elements, such as being a solid
at room temperature, having luster, and having a high melting point. Silicon also has properties that
are similar to those of nonmetal elements. For example, it is brittle and
inductile. The electrical conductivity of
silicon is somewhat like both metals and nonmetals, making it useful as a
semiconductor.
In conclusion, the element that is
not considered to be a metal is silicon, or answer choice (A).
