Acids and bases are substances defined by how they interact with hydrogen ions, hydroxide ions, or electron pairs. In water, their behavior is commonly described with pH, a logarithmic measure related to hydrogen-ion activity. Acids have greater acidic activity, bases have greater basic activity, and a neutral solution has balanced acidic and basic ion activity. The chemistry appears in foods, water, soil, cleaning products, biological…
Momentum is a measure of motion that depends on both an object’s mass and velocity. In a collision, interacting objects exert forces on each other for a short time, changing their individual momenta. People often describe this as motion being transferred from one object to another. More precisely, momentum and energy are redistributed during the interaction, while the total momentum of an isolated system remains…
Conservation of energy is the physical law that says energy can be transferred or transformed, but the total amount is conserved. A falling object can turn gravitational potential energy into kinetic energy. Friction can turn organized motion into internal energy. Heating can transfer energy into matter, while work can transfer energy into or out of a system. The forms and locations change; the energy accounting…
Wave-particle duality is the quantum behavior in which light and matter produce wave-like effects such as interference and diffraction, yet are detected or exchanged in discrete, particle-like events. A photon can arrive at a detector as one localized event while many photons sent through two slits build an interference pattern. Electrons can do the same. Quantum mechanics describes these observations without requiring a photon or…
