Which of the following is not a characteristic of ceramics?

The choice that is not a characteristic of ceramics is high thermal conductivity. Ceramics are generally known for their exceptional properties such as high strength, high hardness, and the ability to resist wear due to their small grain sizes.

High strength in ceramics allows them to withstand significant loads without fracturing, making them suitable for various structural applications. The high hardness characteristic enables ceramics to resist indentation and scratching, which is why they are often used in wear-resistant applications and cutting tools. Small grain sizes contribute to the overall mechanical strength and toughness of ceramics. Fine grains can enhance properties due to the increased surface area and the effects of grain boundaries, which can impede the propagation of cracks.

In contrast, ceramics typically exhibit low thermal conductivity, making them poor conductors of heat. This property is advantageous in applications where insulation is desired, but it sets ceramics apart from materials like metals, which are known for their high thermal conductivity. Thus, the statement about ceramics possessing high thermal conductivity does not align with their established material properties.