pharmacy 03(الخمس)

the liquid crystalline state is also called.....(mesophase)

شيت6 ..... ...... the materials in this state are intermediate between the liquid and solid states. (liquid crystalline; mesophase) 2 ✅

..... and...... based units are.... and..... with..... melting points while....... are..... and have...... melting points. (ions; atoms) (hard;brittle;high) (molecular crystals;soft;low)

Crystalline solids, unlike liquids and gases, have...... and....... (definite shapes) (an orderly arrangement of units)

The structural units of crystalline solids, such as......؛........ and.....؛ , are arranged in........ or.......... (ice, sodium chloride, and menthol) (fixed geometric patterns or lattices)

ش2.. The various crystal forms are divided into.......( six distinct crystal systems) They are, together with examples of each....؛.....؛.....؛....؛.....؛.....؛.[(cubic (sodium chloride), tetragonal (urea), hexagonal (iodoform), rhombic (iodine), monoclinic (sucrose), and triclinic (boric acid)].

Explain the significance of the attractive forces between molecules in relation to the critical temperature.؟ _The attractive forces between molecules cause the particles to "stick" together, and the critical temperature marks the point where these forces become negligible.

critical pressure,the highest vapor pressure that the liquid can have

critical temperature: above which a liquid can no longer exist

_the molecules are brought within the sphere of the van der Waals interaction forces and pass into the liquid state.. •Because of forces, liquids are considerably denser than gases and occupy a definite volume.