In today’s lesson, we explored the properties and safety measures for working with acids and alkalis, focusing on their effects on litmus paper. Both hydrochloric acid and sodium hydroxide were used to demonstrate that acids change blue litmus paper to red, while alkalis change red litmus paper to blue. Additionally, the lesson highlighted that alkalis, such as those found in detergents, can feel slippery, which is why caution is required when they are used for cleaning.