Video Transcript
Which of the following is not a
common property of most transition metals? (A) Transition metals react slowly
or not at all with water. (B) Transition metals react slowly
or not at all with acid. (C) Transition metals form colored
compounds. (D) Transition metals have a low
density. Or (E) transition metals have a
high melting point.
Let’s go through each statement to
see whether or not it is a common property of most transition metals.
Statement (A) says that transition
metals react slowly or not at all with water. We know that this is a true
statement because when transition metals are placed in water or get wet, they tend
to remain unaffected for long periods of time or forever. You can see this if you’ve ever
owned a piece of gold or silver jewelry. It does not react or break down
when wet.
A similarly slow or nonreactive
property can be observed in the presence of acid. Most transition metals will react
but very slowly. And some, like gold, silver, and
platinum, will not react with any common acid. This means that answer choice (B)
is a common property of these metals and so is not the correct answer.
Transition metals form many
oxidation states. The electronic properties of these
various states give rise to many beautifully colored compounds. For example, chromium can exist as
a plus-two, plus-three, or plus-six oxidation state corresponding to blue, green,
and orange. And so we can say that answer
choice (C) is not the correct answer.
Answer choice (E) is an intrinsic
property of transition metals. Elements like vanadium, iron, and
copper all have melting points well above 1000 degrees Celsius. And so we can eliminate answer
choice (E).
This leaves us with answer choice
(D). Transition metals do not tend to
have low densities. In fact, they tend to have high
densities and are usually strong and hard materials. You can see that when compared to
alkali metals, like sodium and magnesium, transition metals are three to four times
more dense.
And so we can revisit the
question. Which of the following is not a
common property of most transition metals? And the correct answer is (D);
transition metals have a low density.
