Is the Core composed of Iron and Nickel?

Contrary to common belief, we cannot be certain of the composition of the Core of our planet because we do not have samples of it. We base our assumption on evidence elsewhere:

• The Earth's electromagnetic field implies that there is Iron in the Core.
• Ironic Meteorites from space have a composition of Nickel and Iron. They have the same density as the Core. We therefore say that at the formation of the Earth, such meteorites were accumulated to form the core of the planet.

Alternatively, the core could be composed of radioactive elements, which is what supplies the Earth with a constant energy supply. This is shaky however, as it leaves much unexplained. Until there is concrete evidence from below the earth's surface, we cannot know for sure, but for all intents and purposes, yes, it is.