* Borax and glue react: Borax (sodium borate) reacts with the polyvinyl alcohol (PVA) in glue. This reaction forms cross-links between the PVA molecules.
* New substance formed: The cross-linking creates a new, three-dimensional polymer network. This network is stronger and more rigid than the original PVA molecules in the glue.
* Change in properties: The resulting substance, known as slime or goo, has very different properties than either borax or glue alone. It is elastic, viscous, and non-Newtonian.
Key indicators of a chemical change:
* Formation of a new substance: The slime is a completely new substance, distinct from the original glue and borax solution.
* Change in properties: The slime exhibits properties (elasticity, viscosity) not found in either the glue or borax solution.
* Irreversible: The process is typically irreversible, meaning you can't easily separate the slime back into borax and glue.
In contrast, a physical change involves only a change in form or appearance, not the composition of the substance. For example, melting ice is a physical change because the water molecules remain the same, just arranged differently.
