Question

Which process is an example of a chemical change?

a metal railing rusting in damp weather
a piece of wood shrinking as it dries out
alcohol evaporating from a cotton swab
steam rising from a boiling pot of soup

Answer 1

Chemical Energy is energy stored in the bonds of chemical compounds (atoms and molecules). It is released in a chemical reaction, often producing heat as a by-product (exothermic reaction). Batteries, biomass, petroleum, natural gas, and coal are examples of stored chemical energy. 

Answer 2

Answer: A metal railing rusting in damp weather.

Explanation:

A chemical change is one in which a new substance is formed during the process of this change and it's not reversible.

A metal railing rusting in damp weather is an example of a chemical change because a new substance called Rust (Fe2O3) you is formed when iron reacts chemically with air.