This document discusses crystals and provides examples of different types of crystal compounds, including sodium chloride, copper(II) sulphate, potassium chromate(VI), and potassium dichromate. It notes that crystals have fixed geometrical shapes like cuboids and prisms, with flat surfaces and sharp angles, and that the angles between neighboring surfaces are always the same for a given substance, even if the crystals are different sizes.

1. Let’s Discover Salt Crystals

2. Sodium Chloride, NaCl

3. Copper(II) sulphate, CuSO4

4. Some examples of Crystals

5. Potassium Chromate(VI), K2CrO4

6. Potassium dichromate(K2Cr2O7)

7. Physical Properties of Crystals
 Have fixed geometrical shapes such as a
cuboid, rhombic or prism
 Have flat surfaces, straight edges & sharp
angles.
 Have fixed angles between two neighbouring
surfaces
 Crystals of the same substance have same
shapes but may be in different sizes

8. All crystals have fixed geometrical shapes

9. All crystals have fixed geometrical shapes

10. All crystals have fixed geometrical shapes