Asbestos – properties and identification for building materials Which of the following statements correctly describe asbestos used in building products?

Introduction / Context:
Asbestos refers to a group of naturally occurring fibrous silicate minerals historically used in building due to their heat resistance, chemical stability, and fibrous texture. Although modern practice restricts asbestos because of health hazards, older specifications and exam questions focus on recognizing its characteristic properties and uses in insulation and fire-resistant products.

Given Data / Assumptions:

• We refer to historical/materials-science properties, not current regulatory guidance.
• Statements include thermal and electrical insulation, fire and acid resistance, density, and tactile description.
• Representative values are considered acceptable.

Concept / Approach:

Asbestos fibers show high thermal resistance, low thermal conductivity, and good dielectric properties, making them suitable (historically) as heat and electrical insulators. They are noncombustible and generally resistant to many acids. Reported specific gravities vary with mineral type; values near 2.5–3.3 are cited across asbestos species. The silky, flexible feel of fibers is a common descriptive property.

Step-by-Step Solution:

Verification / Alternative check:

Materials references list chrysotile and amphibole asbestos with densities in the cited range, confirm noncombustibility, and note historical insulation uses.

Why Other Options Are Wrong:

Each individual statement is consistent with widely reported characteristics; thus, the combined choice is correct.

Common Pitfalls:

Confusing modern regulatory bans with material properties; assuming a single fixed SG for all asbestos types; forgetting that “excellent insulator” historically referred to both heat and many electrical applications.

Final Answer:

All of the above