Is burning a wood splint a chemical or physical change?

The burning of wood is a chemical change.

Explanation:

A chemical change (chemical reaction) is a change of materials into other, new materials with different properties, and one or more new substances are formed. Burning of wood is a chemical change as new substances which cannot be changed back (e.g. carbon dioxide) are formed. For example, if wood is burned in a fireplace, there is not wood anymore but ash.

While, Physical change is opposite of a chemical change is a physical change. Physical changes are a change in which no new substances are formed, and the substance which is changed is the same. For instance, if a stick of wood is broken, there is still a stick of wood; it is just broken.

Conclusion:

Burning Wood is an example of a chemical change that is not reversible.

answer:

technetium is the most reactive. this is followed by silver. the least reactive out of these three elements is strontium.