Electromagnets come in both large and small scales—from big machinery in scrap yards to hard disk drives. Here's a resource that provides directions for building a variable electromagnet on a stand. Scholars then experiment with the...

What variables change heart rate? Young scientists observe the beating heart in Daphnia to understand these variables. They make changes in temperature, chemicals, and other factors as they graph the heart rates. Analysis questions help...

How do scientists prove tiny living things respire? Young scientists build a respirometer and measure respiration rates in living creatures. By comparing the measurements of both plants and animals, they understand the similarities.