Does the following statement describe a chemical or a physical change?

The gas tungsten (VI) fluoride decomposes at high temperatures to give fluorine gas and tungsten metal.

Also, which substance (or mixture of substances) undergoes this change? Please select all the correct answers.

		The statement describes a chemical change that occurs during decomposition.
		The statement describes a physical change that occurs during decomposition.
		Tungsten and fluorine undergo the described change.
		Tungsten (VI) fluoride undergoes the described change.