The short answer: 20 (composite score) is the national ACT average. About half of students score above that, and half of students score below. The top 25% of ACT takers score about 24 or more, so if your score is above 24, that's excellent.
1 SavinâNorov machine gun. 2  Space Network, a NASA relay satellite system. 3  Sthene, an obsolete unit of force or thrust in the metre-tonne-second system of units. 4  Substantia nigra, a brain structure. 5  Supernova, a stellar explosion, in astronomy and cosmology.  Tin, a metallic element with chemical symbol Sn.
In chemistry, a hydron is the general name for a cationic form of atomic hydrogen, represented with the symbol H+ . The term proton refers to the cation of protium, the most common isotope of hydrogen.nlike other ions, the hydron consists only of a bare atomic nucleus. The hydron (a completely free or naked hydrogen atomic nucleus) is too reactive to occur in many liquids, even though it is sometimes visualized to do so by students of chemistry.