An element is any substance that cannot be broken down into simpler substances. The smallest unit of an element is called an . compound

gene

atom

cell

An Atom

Explanation:

An atom is the smallest unit of matter

answer: the rate of diffusion increases with increase in temperature.

increase in temperature, increases the molecular/particles speed (kinetic energy. diffusion means movement of particles through the material.

generally, the heavier the particle the more it interacts with the environment and more the temperature matters. so higher temperature results in higher diffusion.

by cartels in other countries, shipped by air, mail, or land. i cant really see your answer choices : /