This laboratory experiment offers an engaging educational opportunity to instruct students on the practical applications of hydrated and anhydrous Cobalt Chloride in measuring humidity levels. Aligned with the MS-ESS2-5 standard, the "Determining Relative Humidity (Weather Inquiry)" lab for middle school students seamlessly integrates chemistry concepts with meteorological phenomena. The detailed lesson plan provides comprehensive guidance, including a step-by-step procedure and a thorough answe