Video Transcript
Which of the following is not a
common property of the transition metals? (A) They are good catalysts. (B) They form colorful ions. (C) They are good thermal
conductors. (D) They form multiple stable
ions. Or (E) they are easily
vaporized.
There are many transition metal
elements on the periodic table. And there are a few properties that
are common to most of them. Most transition metals are
effective catalysts. Iron metal, for example, speeds up
the Haber process, which is one of the earliest and most useful industrial chemical
processes. In the Haber process, an iron
transition catalyst is used to facilitate the reaction of nitrogen gas and hydrogen
gas to form ammonia, which is used in the production of fertilizer. There are hundreds of examples
including the use of platinum, nickel, and palladium as effective catalysts as
well. And so we can eliminate answer
choice (A).
Transition metal compounds can be
quite colorful because the transition metals have electrons in partially filled
d-orbitals that can absorb and reflect certain types of visible light. Many transition metals can even
form multiple stable ions, leading to a rainbow of colorful oxidized transition
metal compounds. For example, chromium can exist in
three oxidation states. As a plus two ion, it’s bright
blue. As a plus three ion, it’s
green. And plus six hexavalent chromium is
bright orange. And so we can eliminate answer
choices (B) and (D) because they are common properties of most transition
metals.
Transition metals like copper and
iron are also extremely good conductors of heat and electricity. This property is why we use these
metals to make items like pots and pans we use to cook food. And so we can also eliminate answer
choice (C).
And that leaves us with answer
choice (E). Transition metals tend to have high
melting points and even higher boiling points. For example, iron has a boiling
point of about 2862 degrees Celsius, and cobalt is 2927 degrees Celsius. And at this point, we can revisit
the question. Which of the following is not a
common property of the transition metals? And the correct answer is answer
choice (E): they are easily vaporized.
