What Are Solutes & Solvents? A solution is a mixture where one substance dissolves into another evenly. The solute is the substance that gets dissolved (example: salt, sugar, or gas like oxygen). The solvent is the substance that dissolves the solute (example:...

What Is a Wheel and Axle? A wheel and axle is a simple machine that helps us move or lift objects more easily. It has two main parts: a large wheel and a smaller axle (a rod that goes through the wheel’s center). When one part turns, the other turns, too, reducing the...

What Is the Food Pyramid? The food pyramid is a guide that shows how to eat a balanced diet by choosing the right types and amounts of foods. The pyramid has layers, with the largest group (grains) on the bottom and the smallest (fats and sweets) at the top. The main...

What Is Capillary Action? Capillary action is how water moves through tiny spaces—sometimes even uphill! Capillary action happens when water climbs up small spaces, like inside a paper towel or a plant stem. It works because of two forces: Adhesion – water sticks to...

Motion Illusions & Brain Tricks Optical illusions happen when our brain and eyes don’t work together as we expect. Our eyes collect light and images, but the brain tries to make sense of them. Sometimes, the brain makes guesses based on experience, but those...

What is Combustion? Combustion is a chemical reaction that releases energy through heat and light.  Combustion is a chemical reaction between a fuel (such as wood, gas, or oil) and oxygen from the air. This reaction is exothermic, releasing energy (primarily as heat...

What is a Physical Change? A physical change affects a substance’s form or state, not its chemical identity. The molecules stay the same, but their arrangement or movement changes. No new substance is created. A physical change affects only physical properties (like...

How Green Engineering Works Green engineering uses technology to solve problems while protecting the environment. Engineers design machines, buildings, and products that use less energy and create less pollution. Renewable energy sources like solar panels, wind...

How 3D Printing Works 3D printing builds objects by stacking material layer by layer. 3D printing begins with a digital design created using specialized computer-aided design (CAD) software. The printer reads the design and "slices" it into hundreds or thousands of...

How Roller Coasters Work Roller coasters rely on fundamental physics principles, including gravity, potential energy, and kinetic energy. Initially, a lift hill or launch provides the coaster with potential energy, a form of stored energy. As the coaster drops,...