the mass of the solute by gram which dissolved in 100 gram of solvent o form a saturated solution at standard conditions

They are all decomposition reactions.

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.

The answer is 4 i don't know if its right let me see.

Ibelieve its because the stove is a cleaner burning fuel