What are the physical and chemical changes that occur in fireworks?

Answer 1

Fireworks, which are also known as pyrotechnics, are basically devices that contain burning compounds. The most common type of display firework is the aerial shell, which is fired from a mortar tube. These fireworks typically have four components: a lift charge, a time-delay fuse, a breaking charge and a light/effect generator. The lift charge is generally black powder, a compound that burns rapidly and propels the shell from its tube. The lift charge also ignites the delay fuse when it fires. The delay fuse is usually a black powder fuse with a delay of a few seconds, and it is designed to ignite the break charge when the shell reaches the appropriate height. The purpose of the break charge, which sits at the center of the lofted shell, is to explode, thereby igniting and scattering the shell's contents. This break charge is generally finer-grained black powder than the lift charge and more highly confined, which causes the shell to explode. The payload of the shell usually comprises small spherical pellets of pyrotechnic composition designed to generate light. These capsules burn from the outside inward, and color changes are obtained by layering different compositions on top of one another.

Answer 2

Physical changes:

Temperature rises, solid or liquid change to gas.

Chemical : Heat abd light released due to chemical reactions, constituent of fireworks altered irreversibly due to combustion