Isotopically pure diamond Isotopically pure diamond An isotopical pure diamond is a type of diamond that is composed entirely of one isotope of carbon. Isotopically pure diamonds have been manufactured from either the more common carbon isotope with mass number 12 (abbreviated as C) or the less common C isotope. Compared to natural diamonds that are composed of a mixture of C and C isotopes, isotopically pure diamonds possess improved characteristics such as increased thermal conductivity. Thermal conductivity of diamonds is at a minimum when C and C are in a ratio of 1:1 and reaches a maximum when the composition is 100%
Chemical element For example, the formula for heavy water may be written DO instead of HO. Only about 4% of the total mass of the universe is made of atoms or ions, and thus represented by chemical elements. This fraction is about 15% of the total matter, with the remainder of the matter (85%) being dark matter. The nature of dark matter is unknown, but it is not composed of atoms of chemical elements because it contains no protons, neutrons, or electrons. (The remaining non-matter part of the mass of the universe is composed of the even more mysterious dark energy). The