Which layer of the Earth is believed to mainly consist of metallic iron and nickel?

The core is the layer of the Earth that is primarily composed of metallic iron and nickel. This inner layer is divided into two parts: the inner core, which is solid and very hot, and the outer core, which is liquid and responsible for generating Earth's magnetic field through its movement. The high density of the core, due to the presence of these heavy metals, supports the scientific understanding that it plays a critical role in the planet's overall structure and dynamics.

In contrast, the continental crust, upper mantle, and oceanic crust are primarily composed of lighter, silicate minerals. The continental crust consists of a variety of rock types, while the oceanic crust is primarily made up of basalt. The upper mantle, which lies beneath the crust, is composed of silicate minerals as well, and while it contains some metals, its composition significantly differs from that of the core. Thus, the core stands out as the layer that predominantly consists of metallic iron and nickel.