What is a substance that cannot be broken down to other substances by ordinary chemical means?

The correct answer is an element.

Explanation:

An element refers to a component whose atoms comprises a similar number of protons, or it can be said that the atoms of a specific element exhibit the same atomic number. Chemically, they are the simplest components, which cannot be further differentiated by any chemical means. The elements can get converted into other elements with the help of nuclear methods.

before, trains worked using the steam engine. thus, it uses heat so it is crucial to apply heat balance. the steam engine absorbs energy during the stage of boiling water. so, this is the endothermic reaction. when the steam is used to work the piston, it has to release this energy through running the train. the excess energy is released as an exhaust to the chimney. this is the exothermic process because it releases energy to the surroundings.

the answer

b.) bowling ball