Asealed, rigid l.0-liter cylinder contains he gas at stp. an identical sealed cylinder contains ne gas at stp. these two cylinders contain the same number of(1) atoms(2) electrons(3) ions(4) protons

the mantle

explanation:

earth is divided into three layers: the crust or the outermost layer on which we live; the underlying, middle layer - the mantle - and the core (the innermost layer of earth).

i don't see a text, but i am gonna assume this *orbit* the curved path, usually elliptical, described by a planet, satellite, spaceship, etc., around a celestial body, as the sun.