The metallic layer at the earth's center is the inner core of the interior part of earth.
Step-by-step explanation:
Inner core is the deepest layer of the planetary core and has the metallic layer. The metals present are in abundance of Nickel and Iron. The element mentioned are present in form of different alloys in the core.
It has some other metals as well like the silicon with oxygen and Sulphur. There are estimated composition of nickel for about 10 percent and other element of lighter weight to be around 3 percent.