In materials science and manufacturing, ordinary glass for windows and bottles is mainly made from a mixture of which basic raw materials?

Introduction / Context:
Glass is a widely used material in buildings, containers, optical devices and everyday products. Understanding what raw materials go into ordinary glass is part of basic chemistry and general science knowledge. This question asks you to identify the main ingredients used in manufacturing common soda-lime glass for windows, bottles and many household items.

Given Data / Assumptions:

• We are talking about ordinary soda-lime glass, not speciality glasses.
• Silica (silicon dioxide) is known to be a major component of glass.
• Other metal silicates and fluxes are added to adjust melting point and properties.
• Common salt (sodium chloride) is different from soda ash (sodium carbonate).

Concept / Approach:
Ordinary glass is primarily composed of silica, which comes from sand. Pure silica has a very high melting point, so other materials are added to lower the melting temperature and improve workability. These include soda (sodium carbonate) and lime (calcium oxide), which react to form sodium and calcium silicates. The resulting material is often called soda-lime-silica glass. Although sodium compounds are present, manufacturers do not simply mix table salt with sand; they use soda ash and limestone or other mineral sources. Therefore, the correct simplified description is that glass is made from sand and other silicates, not from salt and sand or salt and silicates.

Step-by-Step Solution:
Step 1: Recall that the main ingredient in most glass is silica, chemically SiO2, obtained from sand.Step 2: Remember that soda and lime are added to produce sodium and calcium silicates, which form the glass network.Step 3: Recognise that the resulting mixture is often described as silica plus other silicates.Step 4: Examine option A, which states sand and silicates, and see that it matches this description.Step 5: Note that common salt (sodium chloride) is not the usual raw material; soda ash is used instead, so options B and C are misleading.Step 6: Conclude that the accurate simplified statement is that glass is made from sand and silicates.

Verification / Alternative check:
Chemistry references on glassmaking list the typical batch materials as silica sand, soda ash (Na2CO3), limestone (CaCO3) and sometimes small amounts of other metal oxides for colour or property modification. During melting, these combine to form a silicate network. No standard process uses common table salt as a primary ingredient in ordinary soda-lime glass. This confirms that describing glass as made from sand and silicates is broadly accurate for general-knowledge purposes.

Why Other Options Are Wrong:
Option B, salt and sand, suggests mixing sodium chloride directly with sand, which is not the standard industrial practice for glassmaking. Option C, salt and silicates, again misidentifies common salt as a key glass-forming ingredient instead of soda ash and lime. Option D, none of the above, is incorrect because option A provides a correct high-level description of glass composition.

Common Pitfalls:
Students may confuse common salt with other sodium compounds used in industry or may not differentiate between silica and silicates. To avoid confusion, remember that silica from sand is the main glass-former and that other metal oxides and silicates are added to modify properties. The phrase sand and silicates is a good general summary of typical glass raw materials.

Final Answer:
Ordinary glass is mainly made from sand (silica) together with other silicates such as sodium and calcium silicates.