Which of the following is amorphous?

Solids are classified into crystalline and amorphous based on the arrangement of their constituent particles. Crystalline solids, such as sodium chloride (NaCl) and cane sugar (sucrose), possess a regular, long-range repeating lattice structure and sharp melting points [t1, t7]. Powdered marble consists of calcite, which is a crystalline mineral [c3]. In contrast, amorphous solids lack long-range structural order and do not have a definite melting point; instead, they soften over a range of temperatures [t1, t2]. Glass is a classic example of an amorphous solid, often referred to as a pseudo-solid or supercooled liquid because its particles are not arranged in a regular manner [t1, t6]. While cane sugar and salt are ionic or molecular crystals, glass maintains a disordered internal structure characteristic of the amorphous state [t4, t7].

Sources

1. [1] https://uou.ac.in/sites/default/files/slm/CHE(N)-102.pdf
2. [2] Science ,Class VIII . NCERT(Revised ed 2025) > Chapter 8: Nature of Matter: Elements, Compounds, and Mixtures > 8.5 What Are Minerals? > p. 129