3) In hardware design, a prototype is a hand-built model that represents a manufactured (easily replicable) product sufficiently for designers to visualize and test the design. The word prototype comes from the Latin words proto, meaning original, and typus, meaning form or model.
In chemistry, a salt is an ionic compound which is made up of two groups of oppositely charged ions. The ion with a positive charge is called a cation, and the one with a negative charge is called an anion.
A salt is the combination of an anion (- ion) and a cation (a + ion). Another way to think of a salt is the combination of the anion of a certain acid combined with the cation of a certain base. The neutralization of potassium hydroxide with hydrochloric acid produces water and the salt, potassium chloride.