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.
Radiation that can produce ions when it interacts with matter is called ionizing radiation. Ions are the charged particles that are produced when electrons are removed from their positions in the atoms. Alpha particles, beta particles, x-rays and gamma rays are forms of ionizing radiation.