Final answer:
The ash remaining after trash incineration contains inert materials and can be recycled for various purposes.
Step-by-step explanation:
When trash is incinerated, the ash remaining contains inert materials, meaning substances that are chemically inactive and do not undergo any significant reactions. It does not contain harmful chemicals, toxic gases, or radioactive substances as they are released into the air during the incineration process. The ash can be recycled for various purposes such as landfill cover or construction materials.