Читать книгу Geology and Mineralogy of Gemstones - Karl Wallace, David Turner R. - Страница 19

There are 92 naturally occurring elements out of a total 118 identified, each with its own symbol that acts as a shorthand notation. Some familiar elements and symbols are Au for gold, C for carbon, Ag for silver, and Pt for platinum. Element abbreviations start with a capital letter and if a second letter is present it will always be lowercase. Many elements are already part of our everyday vocabulary, such as oxygen (O), carbon (C), nitrogen (N), and potassium (K) but others are much more obscure, such as beryllium (Be), scandium (Sc), and rhodium (Rh).

Figure 1.2 An atom can lose electrons and become a cation, a positively charged ion. If it gain electrons, it becomes an anion, a negatively charged ion.