The porcelain or ceramic soup bowl is worth $15. **

To remove melted plastic from a ceramic glass cooktop, start by turning off the cooktop and allowing it to cool completely. Once it's cool, use a plastic scraper or a credit card to gently scrape off as much of the melted plastic as possible. Then, apply a small amount of ceramic cooktop cleaner to the affected area and use a soft cloth to gently scrub away any remaining residue. Finally, wipe the cooktop clean with a damp cloth and dry it thoroughly. Avoid using abrasive materials or harsh chemicals, as they can damage the cooktop surface. **

It depends on the specific application and requirements. Turned ceramic, also known as machined ceramic, is typically more precise and can achieve tighter tolerances compared to cast ceramic. However, cast ceramic may be more cost-effective for larger and more complex shapes. Additionally, turned ceramic may have better surface finish and mechanical properties, while cast ceramic may have better thermal shock resistance. Ultimately, the choice between turned and cast ceramic depends on the specific needs of the application. **

An immersion heater can be safely placed in a metal container, as long as the metal is non-corrosive and can withstand the heat generated by the heater. However, it is not safe to place an immersion heater in a plastic container, as the heat can cause the plastic to melt or release harmful chemicals. It is important to always check the manufacturer's guidelines and recommendations for the specific immersion heater being used to ensure safe and proper usage. **

Porcelain and ceramic break at different temperatures depending on the specific type and quality of the material. Generally, porcelain tends to break at higher temperatures than ceramic due to its denser and more refined composition. Porcelain typically breaks at temperatures above 1200 degrees Celsius, while ceramic may break at temperatures ranging from 800 to 1000 degrees Celsius. It is important to handle both materials carefully to prevent breakage during heating or cooling processes. **

If you accidentally swallow a small piece of ceramic or porcelain, it will likely pass through your digestive system without causing harm. However, if the piece is large or sharp, it could potentially cause damage to your throat, esophagus, or stomach. In this case, it is important to seek medical attention immediately. Additionally, ingesting ceramic or porcelain glaze or paint could expose you to harmful chemicals, so it's important to seek medical advice if this occurs. **

Yes, a ceramic cooktop glass can be repaired. Small scratches and minor damage can often be repaired using a ceramic cooktop repair kit, which includes special fillers and polish to restore the surface. However, for more extensive damage such as cracks or large chips, it may be necessary to replace the entire cooktop glass. It is important to follow the manufacturer's guidelines and seek professional help if needed to ensure the repair is done properly and safely. **

Cobalt can become toxic in ceramic or porcelain when it is not properly bound to the material during the firing process. If the cobalt is not fully incorporated into the ceramic or porcelain, it can leach out over time, especially when in contact with acidic foods or liquids. This can lead to the ingestion of cobalt, which can be toxic to the body in high doses. To prevent this, it is important for manufacturers to ensure that cobalt is properly bound to the ceramic or porcelain during the production process. **