Question

a crystal exhibits only three mirror planes, three two - fold rotational axes, and an inversion point (center of symmetry). it belongs to which system?
hexagonal
orthorhombic
triclinic
monolclinic
sportsclinic

Explanation:

1. Recall crystal system symmetry:

• Hexagonal: Has a six - fold axis, more symmetry than given.
• Orthorhombic: Can have three mutually perpendicular two - fold axes, three mirror planes (parallel to the axes), and a center of symmetry, matching the given symmetry (three mirror planes, three two - fold axes, inversion point).
• Triclinic: Has no symmetry other than identity, no mirror planes or two - fold axes as given.
• Monoclinic: Has one two - fold axis, one mirror plane, not matching three of each.
• "Sportsclinic" is not a valid crystal system.

Answer:

Orthorhombic