Temperature: A measure of the average kinetic energy of particles in a substance; the SI unit is the kelvin (K). Scientific Notation: A method of expressing numbers as a product of a coefficient and a...Temperature: A measure of the average kinetic energy of particles in a substance; the SI unit is the kelvin (K). Scientific Notation: A method of expressing numbers as a product of a coefficient and a power of 10, used to handle very large or very small numbers. Slope: A measure of the steepness of a line on a graph; calculated as the rise over the run (Δy/Δx).