KANAKAPURA, Karnataka, India – In this five-room village school fringed by coconut trees, teacher Ravindra K. Nagaiah has a surprise for his 7th-grade science class today.
The day’s topic is “Acids, Bases, and Salts.” Along with the usual supply of litmus strips, hydrochloric acid, and baking soda, Ravindra has prepared small beakers of juice from the hibiscus flower and lemons.