a. is split
b. is painted
d. is cut
Chemical change leads to the formation of new substances. A chemical change is said to have occurred when the piece of wood decays.
A chemical change is said to have occurred when new substances are formed. Hence, in a chemical change, one substance is converted into another.
When a piece of wood decays, a cascade of chemical transformations occur leading to a change in the composition of the wood and carbon dioxide is produced.