How many crystal systems occur in crystalline solids?

Options

A. `5`
B. `10`
C. `14`
D. `7`

Answer

4

Explanation

The basic shape of unit cell is described by a parallelpiped (Now that a parallelepiped is a three dimensional model of parallelogram).A unit cell has three coordinates aces.`X,Y` and `Z`.The cell edges lengths in the three axes are `a,b` and `c` respectively .The angle between `a` and `b ` .`b` and `c` and `c` and `a` are `alpha,beta` and `gamma` respectively.
Based on the relationships among the edge lengths and the axial angles ,there are seven cystals systems,cubic rhombohedral,tetragonal ,orthorhomonic,monoclinic and triclinic.