Zinc is used as a constituent in brass, in some types of batteries, and as a protective coating
on sheet metal ( galvanizing ). Because of its low density, titanium is used in alloys that are important in the production of aircraft and aerospace components. Vanadium and aluminum are alloyed with titanium to produce alloys that are stronger than titanium alone, and one of the common alloys contains 6% aluminum and 4% vanadium. Plating metals with chromium provides protection from rust. Chromium is also used in making various types of stainless steel. Scandium is becoming increasingly important in making tools and small devices where exceptional strength is combined with extremely light weight (the density of Sc is 2.99 g/cm 3 ). It is impossible to imagine an industrialized society in which the transition metals would not be vital commodities. Table 11.2 contains useful data for the first-row transition metals.