17. A substance breaks down into its component elements when it is heated. If 68.0 g of the substance is present before it is heated, what is the combined mass of the
component elements after heating?

Non metal is an element or substance that is not a metal metal is a solid material that is typically hard, shiny, malleable, fusible, and ductile, with good electrical and thermal conductivitymetalloid is an element (e.g., germanium or silicon) whose properties are intermediate between those of metals and solid nonmetals. they are electrical semiconductors.