Which statements describe an element? check all that apply.
an element is a pure substance.
an element is made of only one type of atom.
an element is made of two or more different types of atoms.
an element can be broken down into a simpler form.
an element cannot be broken down into a simpler form.

1. crust 1 the metallic layer at the earth's center 2. inner core 3 the firm layer between the crust and the asthenosphere 3. lower mantle 2 the layer surrounding the inner core 4. asthenosphere 4 the semi-solid layer between the top layer and the upper mantle 5. upper mantle 5 the layer between the asthenosphere and lower mantle 6. top layer 6 the earth's outermost layer 7. outer core 7 the hottest part of the mantle