Video Transcript
Which of the following is
ferromagnetic? (A) Mn2+, (B) Cu2+, (C) Ti2+, (D)
V3+, (E) Fe2+.
First of all, a substance is
considered ferromagnetic if it is able to form a permanent magnet. There are not that many
ferromagnetic elements. Let’s take a look at the magnetic
properties of the period four d-block metals.
Several of these metals are
paramagnetic, which means they are attracted to the magnetic fields of other magnets
but are not permanently magnetic. Paramagnetic substances have
unpaired electrons in their orbitals. We also notice that copper and zinc
are diamagnetic, which means they weakly repel other magnets but are not permanent
magnets.
Diamagnetic substances generally
have only paired electrons in their orbitals. When looking at the electronic
configuration of copper, we might expect it to be paramagnetic because there is one
unpaired electron in the 4s subshell. However, it turns out that copper
is an exception to this rule and is diamagnetic.
Because of their unique structures,
iron, cobalt, and nickel elements and most of their alloys exhibit
ferromagnetism. This means these elements are
permanently magnetic, and not just magnetic when they interact with other
magnets.
Finally, we see that chromium is
antiferromagnetic, which is a type of magnetism we won’t discuss in this video.
When looking at the answer choices,
the ion that is most likely to be ferromagnetic is the iron(II) ion. However, it’s important to note
that iron(II) ions are not ferromagnetic in all of the substances that they are
found in. Therefore, the correct answer is
answer choice (E), Fe2+.
