Answer: B. Elements are represented by chemical formulas.
Elements are pure substances, which means that they cannot be broken down into simpler substances. The element is the most basic substance that exists, breaking it down further means breaking it down into protons, neutrons, and electrons, which is no longer a substance.
Elements have chemical properties that allow them to form different types of bonds with other elements.
However, elements *alone* are not represented by their chemical formulas. Only chemical bonds or ions are represented by a chemical formula.
<span>The best reason I can think of for why we believe that air is a mixture is that freezing air slowly yields different liquids at different temperatures. Liquid nitrogen has a different boiling point than liquid oxygen. They also freeze at different temperatures. If air were only 1 compound, then air in its entirety would have a single boiling point and a single freezing point. </span>
These 5 metals are: zinc,copper,tin,bronze,nickel
ionic bond is formed between ca and cl forming molecule cacl2 ca has 2 velancy and cl has one velancy (ca has 2 electrons in its outer most shell while cl has 1 electron vecancy in its outermost shell). So ca would make bond with 2 cl atoms