Like purple ribbons, blue ribbons represent many things, and among these are two types of cancer, colon cancer and colorectal cancer. Blue ribbons are also used, particularly in Canada, as a symbol for another issue that is related to cancer, anti-tobacco and anti-second-hand-smoke awareness. Light blue ribbons represent prostate cancer and, as an alternative to pink, childhood cancer. Gold is yet another alternative color for childhood cancer.
Hydrogen (chemical symbol H), named after the Greek word for water-forming, is the most abundant element in the Universe. In fact more than nine-tenths of all atoms are hydrogen atoms. It is the stuff of stars, of cold empty space and of the Earth. Hydrogen is found everywhere and in most compounds.ydrogen in water. Water is the most common chemical compound on the surface of the Earth, covering over two-thirds of the Earth's surface. People are also about two-thirds water. Water is a compound of hydrogen and oxygen.
Silicon is the second most abundant element. Silicon dioxide and silicates (salts derived from silicon dioxide) make up about 87 percent of the materials in the Earth's crust. (Source: Tzimopoulos, Nicholas D., et al. Modern Chemistry, pp. 289, 758.) However water is the most common substance on the surface of the Earth. In the atmosphere, Nitrogen is the most common element (78%). It is believed that the core of our planet is mostly made of iron (at very high pressure and density), so iron would be the most common element within the Earth.