There are many more examples. Note that measuring each of these properties will not alter the basic nature of the substance. Examples of chemical properties are: heat of combustion, reactivity with water, PH, and electromotive force.
Mathematical fonts. In mathematical mode you can change the typefaces of the fonts when needed. For instance, it's customary to represent real numbers with a blackboard bold font, or topological spaces with calligraphic font. This article shows several fonts in math mode.
Obviously, Open Sans is the font that is imported. But you can replace it with yours. If it is a single word font, just include the font name after the family=... if it is two words, do as I did and add a + sign between each word. NOTE: The @import line of code should be the very first line in your CSS file.