Plz explain with diagram. i)plane of symmetry ii)center of symmetry iii)an alternating axis of symmetry.

(i)plane of symmetry-when an imaginary plane can divide a crystal in such a way thateach part is exactly mirror -image of each other,then the crystal is said to have a plane of symmetry

(ii)center of symmetry-center of symmetry of a crystal is such a point that any line drawn through it,intersect the surface at equal distance in both direction

(iii)an alterating axis of symmetry-if a crystal is rotated around an imaginary line in such a way that it give same appearance more than once during one complete rotation,then this line is called an alternative axis of symmetry