Final answer:
Hydroxymethane and carbon nonoxide, likely referring to methanol and carbon monoxide, possess the chemical property of combustibility, which involves a chemical reaction with oxygen to release heat.
Step-by-step explanation:
The nature of hydroxymethane, carbon nonoxide, and other gases being discussed refers to a chemical property of these compounds. In looking at options such as combustibility, radioactivity, volatility, and density, the correct choice would be combustibility, which is indeed a chemical property. When a substance like hydroxymethane (presumably a typo for methanol, CH3OH) reacts with oxygen to produce carbon dioxide and water while releasing heat, this indicates its flammability or combustibility.
Such properties are intrinsic to hydrocarbons and related compounds. For example, methane (CH4) is a combustible gas. This characteristic is utilized in analytical techniques like combustion analysis, where hydrocarbons are completely burned in the presence of oxygen to yield carbon dioxide and water, allowing for the determination of their elemental composition.