Statement I: Glass is not considered as a true compound. Statement I : Glass does not have a definite melting point.

Statement I is true because glass is not a true compound in the chemical sense; it is an amorphous solid or a supercooled liquid that lacks a definite chemical formula and long-range periodic atomic arrangement [1]. Unlike crystalline compounds, glass is an inorganic product of fusion that has cooled to a rigid condition without crystallization [1]. Statement II is also true as glass lacks a sharp, definite melting point [1]. Instead, it undergoes a glass transition, softening gradually over a range of temperatures [3]. Statement II correctly explains Statement I because the absence of a definite melting point is a direct consequence of its disordered, non-crystalline structure, which distinguishes it from true crystalline compounds that possess fixed melting temperatures and long-range order. Therefore, both statements are true, and Statement II provides the structural reason for the classification in Statement I.

Sources

1. [1] https://www.sciencedirect.com/topics/materials-science/glass
2. [3] https://en.wikipedia.org/wiki/Glass_transition