Learners make slime from white school glue and Borax detergent. The long chain molecules of the white glue become cross-linked by the Borax into a big network. The result is an even larger polymer of thickened slime. Learners can experiment with the ratios of ingredients and see what effect that has on the resulting slime. Safety note: Borax is an irritant and should be kept out reach of children and pets. While safe in diluted solutions, borax can be harmful if ingested.