The electromagnetic spectrum covers all possible wavelengths and frequencies of radiation. From lowest frequency (longest wavelength) to highest frequency (shortest wavelength) radiation: radio waves → microwaves → infrared waves → visible light → ultraviolet light → X-rays → gamma rays.

An endoskeleton (internal skeleton) is a charateristic of vertebrate animals, including humans.

In the liquid state, molecules flow freely around each other and exist at a higher temperature range than the same substance in a solid state. Liquids maintain a constant volume but their shape depends upon the shape of their container.

Small quantities of certain minerals like iron, calcium, magnesium, and salt are important for nutrition and health.

Velocity and displacement are vector quantities which means each is fully described by both a magnitude and a direction. In contrast, scalar quantities are quantities that are fully described by a magnitude only. A variable indicating a vector quantity will often be shown with an arrow symbol: \(\vec{v}\)