Is the outer core made of metal?
Yes. It is an envelope of molten metal, mostly iron, surrounding an inner core of solid iron-rich metal.
The layered structure of Earth is given at http://www.merrittcartographic.co.uk/earth_structure.html. The nain layers are:
Crust -- a thin layer of solid, rigid rock containing mostly silicate minerals.
Mantle -- a thick layer of mostly silicates, generally richer in magnesium and iron, poorer in other metals, than the crust. The upper layers of the mantle are rigid but there is fluid in the hotter regions below.
Outer core --molten metal, mostly iron, directly underneath the mantle.
Inner core -- a ball of solid iron-rich metal at the center of the Earth, surrounded by the liquid outer core.