Question

Which set of procedures and observations indicates a chemical change?

(1) Ethanol is added to an empty beaker and the ethanol eventually disappears.
(2) A solid is gently heated in a crucible and the solid slowly turns to liquid.
(3) Large crystals are crushed with a mortar and pestle and become powder.
(4) A cool, shiny metal is added to water in a beaker and rapid bubbling occurs.

Answer 1

Option 4 seems to be the one undergoing a chemical change because there is a formation gas from the bubbling that occurs. Chemical change is the change that results to the formation of a new substance. The other options given are examples of physical change.