Exploring Material Hardness: The Scratch Test

Next Generation Science

This video provides a clear, practical demonstration of how to test the physical property of hardness using a simple scratch test. Through a series of systematic trials, a narrator uses a metal nail to attempt to scratch various everyday objects, including a wax candle, plastic brick, glass beaker, and ceramic tile. The results are clearly stated and visually demonstrated, allowing viewers to see which materials resist abrasion and which do not. The content focuses on key scientific themes such as observing physical properties, conducting fair tests, and categorizing matter. It introduces the concept that materials have distinct characteristics that determine their suitability for different uses. The repetitive structure of prediction and observation reinforces the scientific method for young learners. For educators, this video is an excellent tool for introducing units on matter and materials. It models a safe and replicable experiment that can be adapted for the classroom. Teachers can use it to spark discussions about why certain objects are made of specific materials (e.g., why windows are made of glass but candles are made of wax) and to practice the skills of prediction and data recording.