States of Matter: Baking Soda in a balloon, on top of a bottle filled with vinegar makes a gas and fills up the balloon. We've almost finished the matter unit but this might be fun to show them either way.
Weather Teaching Activities Science and reading hands-on activities for students to learn about the different weather pattern. Has good activities for clouds and lightning and tornadoes all things you can relate to the curriculum.
Could have the kids do this, upload to Edmodo, and then include a write-up explaining the different phases. Hands On Science: Phases of the Moon Activities for Kids - Inspire Creativity, Reduce Chaos & Encourage Learning with Kids
Education 325 (Chemistry) Dancing Raisins Science Experiment for Kids - This is such a fun science project for preschool, kindergarten, grade, and grade kids. They will be amazed as they see chemical properties at work.