Video Transcript
What is the only nonmetal element
that exists in a liquid state at room temperature?
All elements can be classified as
either metals, metalloids, or nonmetals. The question mentions a nonmetal
element, so let’s focus on these. Nonmetals all tend to have similar
properties or characteristics. We talk about physical properties
and chemical properties. Let’s focus on physical
properties. Physical properties are those
properties which we can observe and measure without the substance changing its
identity. Physical properties include what
state the element or substance is in at a certain temperature, its melting point,
its boiling point, its density, its color, whether it conducts thermal energy and
electricity, and so on.
Let’s remind ourselves of some
physical properties of nonmetals. Nonmetal elements tend to be
brittle. That is, they tend to break or
shatter when they are hammered. Nonmetals cannot be shaped like
metals can. Most nonmetals do not conduct
thermal energy or electricity well. We say they are poor
conductors. This is opposite to the metals,
which are very good at conducting thermal energy and electrical current. There are a few exceptions
though. For example, the nonmetal graphite,
which is a form of carbon, is very good at conducting thermal energy and
electricity. Nonmetals also all tend to share a
similar characteristic in their appearance. They all tend to appear dull. That is, their surfaces are not
shiny or lustrous like the surfaces of metals.
Now, the question asks us about
another physical property, which is physical state. We are asked to identify the
nonmetal which is a liquid at room temperature. All nonmetals are solids, and a few
are gases at room temperature. Some examples of nonmetals which
are solid at room temperature are carbon, sulfur, and iodine. Nonmetal gases you may be familiar
with are oxygen gas, nitrogen gas, and chlorine gas. There is one nonmetal, however,
which is neither a solid nor a gas at room temperature. And that is the nonmetal
bromine. Bromine is a red-brown liquid at
room temperature. In fact, the only nonmetal that
exists in a liquid state at room temperature is bromine.
