Final answer:
Constants in equations always have the same value and do not change.
Step-by-step explanation:
A constant in an equation always has the same value. For example, the speed of light (c = 2.99×108 m/s), Planck's constant (h), and Avogadro's number (NA) are all examples of constants used in science. Constants are fixed values that do not change and are often represented by letters, such as a, b, or c.