Today is sunny. I learned in science class about mixtures and solutions. Generally, any change that doesn't alter the particles is a physical change. The question came up: is salt dissolving in water a physical change? Indeed, it is. Then, I was asked how to separate sand and salt in a mixture. For the first time, I felt sharp enough to tackle the issue swiftly. I chose to mix the mixture in water; the sand would settle, and the salt would dissolve. Later on, I could evaporate the salty water to extract the solid salt. I feel like a genius!