Question

Draw eclipsed and staggered conformations of ethane.

Answer 1

CH3 CH3  
  the 3 hydrozen atoms are in a plane and attached to one a C in the plane perpendicular to C - C bond.    In eclipsed form, Look along the axis or C - C bond and perpendicular to plane of hydrozen atoms.  Then you find that 3 hydrozen atoms attached to the rear C are exactly behind the front 3.  C is behind C.

In staggered conformation, The H atoms in the front are rotated by some value. So if you look along C - C bond,  3 front H atoms and 3 rear H atoms are all visible.