In this task you will be given a text passage from a trivia quiz. You should choose the category this question belongs to from these categories: History, Science, Social Science, Fine Arts, Literature. You can only choose one category, so if in doubt, please choose the closest match.
Q: An ion of this element is used as a masking agent when performing an EDTA titration of a mixture of magnesium and aluminum. A common inhibitor of serine proteases contains a phosphate group attached to two isopropyl groups and an atom of this element. One compound that contains 3 atoms of this element is used to cleave t-BOC during solid-phase peptide synthesis. When this atom is added to the alpha carbon of acetic acid, it significantly strengthens it via the (*) inductive effect. A powerful Lewis acid is a compound of three atoms of this element attached to boron. Four atoms of this element are attached to the repeating element of Teflon, and an acid of this element is used to etch glass. An ion of the element is commonly added to drinking water. For 10 points, name this most electronegative element with atomic number 9 and symbol F.
A:
Science