As for the etymology the term enemy is derived from Latin language for 'bad friend' (Latin: inimicus). Enemy is a strong word, and emotions associated with the enemy would include anger, hatred, frustration, envy, jealousy, fear, distrust, and possibly grudging respect . As a political concept, an enemy is likely to be met with hate, violence, battle and war. The opposite of an enemy is a friend or ally.
diffusion. 1. The process of rapid random movement of the particles of a liquid or gas which eventually form a uniform mixture. 2. The mixing of substances due to the motion of their particles.
Diffusion occurs in gases and with any substance in a solution. Therefore we can say that the definition of diffusion is as follows: Diffusion: The movement of particles from an area of high concentration to an area of low concentration until they spread out evenly. There are two important rules to remember. The larger the particles the slower the rate of diffusion. The greater the difference in concentration the greater the rate of diffusion. This difference is known as the concentration gradient. Example of diffusion in plant cells; Example of diffusion in animal cells