An element has electronic configurations 2, 8, and 4. It will be classified as

We can determine the atomic number of an element and consequently its identity by adding up its electronic configuration. We can categorise an element into metals, nonmetals, and metalloids by looking at where it occupies space in a periodic chart.

The electronic configuration is as follows: 2, 8, 4. Because of this, there are two electrons in the K shell, eight in the L shell, and four in the M shell. Consequently, there are 14 electrons in all. We can presume that the stated element is silicon because it has an atomic number of fourteen. We can infer from the electrical configuration that the valency is four, making it a group 14 element that belongs to period 3 of the periodic table.
Metalloids include silicon, an element. They are not as good as conductors of metals, but they are better conductors of electricity than non-metals. Almost all electronic components, including computers, mobile phones, and other devices, contain silicon semiconductors, which serve as semiconductors.
As a result, it is evident from the foregoing discussions that the element with the electrical structure 2, 8, 4 can be categorised as a metalloid.

Hence, the correct answer is option C.