What makes a solid crystalline rather than amorphous?
AIt must be transparent
BIts particles are arranged in a repeating pattern
CIt must be very hard
DIt must be made of ions
A crystalline solid has particles arranged in a regular, repeating three-dimensional pattern (lattice). An amorphous solid, like glass, has particles in a disordered arrangement. Crystalline solids can be opaque, soft, or made of atoms or molecules — the defining feature is the ordered pattern.
Question 2 True / False
Glass is an example of a crystalline solid.
TTrue
FFalse
Answer: False
Glass is an amorphous solid, meaning its particles are arranged in a disordered, random pattern rather than a regular repeating lattice. This is why glass does not have natural flat faces or a characteristic geometric shape like crystalline solids do.
Question 3 Short Answer
Why does table salt naturally form small cube-shaped crystals?
Think about your answer, then reveal below.
Model answer: The sodium and chloride ions in salt arrange themselves in a cubic lattice pattern, so the crystal's outer shape reflects the internal arrangement.
In NaCl, sodium ions and chloride ions alternate in a three-dimensional cubic grid. This internal cubic arrangement extends outward, producing the cube-shaped crystals you can see with a magnifying glass. The external shape of a crystal is a direct reflection of how its particles are organized inside.