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.
(October 2014) A hydrogen ion is created when a hydrogen atom loses or gains an electron. A lone positively charged hydrogen ion (or proton) can readily combine with other particles and therefore is only seen isolated when it is in a gaseous state or a nearly particle-free space.