Video Transcript
What is the most abundant
transition element in Earth’s crust?
The Earth has several distinct
layers. The innermost portion is the inner
core. Next is the outer core. Third is the mantle layer. And the outer layer is the
crust. We are asked about the most
abundant transition element in this crust layer.
The periodic table is divided into
sections. The blocks shown in pink are the
transition metals and the inner transition metals. The last group of the d block,
which is shaded here, are not technically transition metals according to the IUPAC
definition. But many scientists loosely refer
to these as transition elements too. We won’t look at this definition
here. Let’s rather focus on identifying
which of these elements is the most abundant in Earth’s crust.
The two most abundant elements in
Earth’s crust are oxygen followed by silicon. These are not transition
elements. Next come aluminum, iron, calcium,
then sodium. Iron is a transition metal. Then, we have even smaller amounts
of magnesium. And the last portion of this pie
chart is a combination of various elements, including titanium and hydrogen. Titanium is a transition
element. All other elements, including other
transition elements, are too rare to even show as a slice on this chart.
Thus, the most abundant transition
element in the Earth’s crust is iron. Iron is mechanically robust. It is used in economically
important alloys, such as steel. Iron is also one of the most
abundant chemical elements in the solar system, as it forms in the final stages of
silicon burning in stars. And scientists speculate that most
solid planets have a high content of the element iron. And they know that there is lots of
iron in other layers of the Earth too.
We should appreciate, however, that
iron is rarely present in the Earth in its elemental or pure form. It is usually found in
iron-containing ores, such as hematite.
Finally, we have seen that the top
three most abundant elements, oxygen, silicon, and aluminum, are not transition
elements. And we have seen that the fourth
most abundant element in the crust is iron, which is a transition element. So which is the most abundant
transition element in Earth’s crust? The answer is iron.
