Men's hats are sized according to diameter while women's are based on circumference. The most common hat size for men is 7 1/8 and for women, 221. To measure the size of a person's head, use a flexible tape measure to measure the circumference at the widest part of the head, usually an inch above the eyebrows.
Arrhenius argued that bases are neutral compounds that either dissociate or ionize in water to give OH-ions and a positive ion. NaOH is an Arrhenius base because it dissociates in water to give the hydroxide (OH -) and sodium (Na +) ions.
Ions can be created by chemical means, such as the dissolution of a salt into water, or by physical means, such as passing a direct current through a conducting solution, which will dissolve the anode via ionization. Ions consisting of only a single atom are atomic or monatomic ions.