A simple demonstration adaptable to classroom conditions is presented, which involves the preparation of raffle tickets using filter paper and the solution of selected fluorophores. With an appropriate dilution, the text written on the tickets is not visible to the naked eye; however, it becomes readable once put under a UV lamp. Besides being a…

In this article, a consecutive series of four hands-on experiments are recommended to teach the colors of paint/pigment and their mixtures. These activities, which are effective in learning about how to make a simple observation and help to build argument-based knowledge about colors, offer an integrated and innovative way of teaching colors of…

Recognition of interference and diffraction patterns is a difficult task for both high-school and university students. Many students fail to observe important features of particular patterns and identify the differences among similar patterns. In this study, we investigated if performing students' investigative experiments can help high-school…