Symbols of common elements

0 Oxygen A gaseous element essential to human life comprises about 20% of the air 

C Carbon All living matter contains carbon compounds 

Cl Chlorine Abundant element, always combined in nature with other elements 

Na Sodium Combined with other elements in nature 

P Phosphorous Combined with other elements in nature another element essential to life 

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Figure 1 shows the symbols of common elements used in electronic circuits. These can be classed as either passive components, such as resistors, capacitors, inductors, and diodes, or active components, such as bipolar and field-effect transistors, and silicon-controlled rectifiers (SCRs). Some of the key features and physical characteristics of these devices are summarized in the first two sections of this chapter. 

A short list of symbols of common elements is given in Table 1 -2. Learning this list will be helpful. Many s)mibols consist of the first one or two letters of the element s English name. Some are derived from the element s Latin name (indicated in parentheses in Table 1-2) and one, W for tungsten, is from the German Wolfram. Names and symbols for additional elements should be learned as they are encountered. 

Table 1.1 lists the names and symbols of several elements that are probably familiar to you. In either free or combined form, they are commonly found in the laboratory or in commercial products. The abundances listed measure the relative amount of each element in the earth s crust, the atmosphere, and the oceans. 

TABLE B.2 Element Some Isotopes of Common Elements Atomic number, Symbol Z Mass number, A Abundance, %... 

TABLE 11.20 Elements Precipitated by General Analytical Reagents This table includes the more common reagents used in gravimetric determinations. The lists of elements precipitated are not in all cases exhaustive. The usual solvent for a precipitating agent is indicated in parentheses after its name or formula. When the symbol of an element or radical is italicized, die element may be quantitatively determined by the use of the reagent in question. ... 

For convenience, chemists use symbols of one, two, or three letters to represent the elements. The first letter of a symbol is always capitalized, but any following letters are not. For example, Co is the symbol for the element cobalt, whereas CO is the formula for the carbon monoxide molecule. Table 1.1 shows the names and symbols of some of the more common elements a complete list of the elements and their symbols appears inside the front cover of this book. The symbols of some elements are derived from their Latin names—for example, Au from aurum (gold), Fe from ferrum (iron), and Na from natrium (sodium)—while most of them come from their English names. Appendix 1 gives the origin of the names and lists the discoverers of most of the elements. 

TABLE 2.3 Isotopic Distribution of Common Elements Element Symbol Nominal Mass Exact Mass Relative Abundance... 

To show the outermost electrons of an atom, we commonly use a representation called a Lewis structure, after the American chemist Gilbert N. Lewis (1875-1946), who devised this notation. A Lewis structure shows the symbol of the element, surrounded by a number of dots equal to the number of electrons in the outer shell of an atom of that element. In Lewis structures, the atomic symbol represents the nucleus and all filled inner shells. Table 1.3 shows Lewis structures for the first 18 elements of the Periodic Table. As you study the entries in the table, note that, with the exception of helium, the number of valence electrons of the element corresponds to the group number of the element in the Periodic Table for example, oxygen, with six valence electrons, is in Group 6A. 

Figure 5.9 (a) Table of common elements, with symbols and atomic numbers, (b) Partial periodic table showing the symbols and locations of the more common elements. The table in part (a) and the list below identify the elements that you should be able to recognize or write, referring only to a complete periodic table. Associating the names and symbols with the table makes learning them much easier. The elemental names are... 

When you write chemical equations, it is absolutely essential that you write the formulas of these seven diatomic elements as two-atom molecules with a subscript 2 following the symbol of the element. Failure to do so is probably the most common mistake made by beginning chemistry students. The formulas of other elements are the same as their elemental symbols. No subscript is used. 

Another way to show valence electrons uses Lewis symbols, which are also called electron-dot symbols. The symbol of the element is surrounded by the number of dots that matches the number of valence electrons. Dot symbols for the main group elements in Period 3 are given in Table 11.1. Paired electrons, those that occupy the same orbital, are usually placed on the same side of the symbol, and single occupants of one orbital are by themselves. This is not a fixed rule exceptions are common if other positions better serve a particular purpose. 

Table B-1 SI Measurement Table B-2 Unit Symbols Table B-3 Symbols Table B-4 Physical Constants Table B-5 Enthalpy of Combustion Table B-6 The Elements Symbols, Atomic Numbers, and Atomic Masses Table B-7 Common Ions Table B-8 Water-Vapor Pressure Table B-9 Densities of Gases at STP Table B-10 Density of Water Table B-11 Solubilities of Gases in Water Table B-12 Solubility Chart Table B-13 Solubility of Compounds Table B-14 Enthalpy of Formation Table B-15 Properties of Common Elements...

Rather than full names, scientists identify elements with one- or two-letter symbols. Some common elements and their symbols are carbon, C oxygen, O nitrogen, N hydrogen, H chlorine. Cl and, sulfur, S. These chemical symbols are derived from the letters of the name of the element. The first letter of the symbol is capitalized, and the second (if applicable) is lowercase. Symbols for some elements known from ancient times come fiom earlier, usually Latin, names for example, Cu from cuprum (copper), Ag from aurum (gold), and Fe from/ern[Pg.12]

Al. no. Element Symbol At. wt. Mass number of common isotopes Per- iodic group Valency - + Density at 20° C (g em- ) Boiling point rc)... 

To answer the question one has to examine carefully the permutations which correspond to the 24 rotations of the octahedron. We partition these permutations into cycles and assign to each cycle of a certain order k the symbol f. assign to a cycle of order 1 (vertex which is invariant under rotation), f to a cycle of order two (transposition), /g to a cycle of order three, etc. A permutation which is decomposed into the product of cycles with no common elements is represented by the product of the symbols /. associated with the corresponding cycles. Thus the rotations of the octahedron are described by the following products ... 

Just like chemists today, ancient Egyptians also used symbols as well as words to represent common elements and compounds. Electrum is an alloy of silver and gold. 

Each element has been named and, for convenience, has been given a nickname—a shorthand symbol of one or two letters. Thus the element carbon is symbolized by the letter C, the element neon by the letters Ne. The symbols are adopted by international agreement among chemists. Eleven of the elements have names derived from the capitalized first letter of the Latin name of the element and, if necessary, by a second letter (uncapitalized). These eleven include seven common metals known to the ancients. (See Table 2-V.)... 

The chemical formula of a compound represents its composition in terms of chemical symbols. Subscripts show the numbers of atoms of each element present in the smallest unit that is representative of the compound. For molecular compounds, it is common to give the molecular formula, a chemical formula that shows how many atoms of each type of element are present in a single molecule of the compound. For instance, the molecular formula for water is H20 each molecule contains one O atom and two H atoms. The molecular formula for estrone, a female sex hormone, is Clgl-I2202, showing that a single molecule of estrone consists of 18 C atoms, 22 FI atoms, and 2 O atoms. A molecule of a male sex hormone, testosterone, differs by only a few atoms its molecular formula is (lyH2802. Think of the consequences of that tiny difference ... 

In a balanced chemical equation (commonly called a chemical equation ), the same number of atoms of each element appears on both sides of the equation, chemical equilibrium A dynamic equilibrium between reactants and products in a chemical reaction, chemical formula A collection of chemical symbols and subscripts that shows the composition of a substance. See also condensed structural formula empirical formula,- molecular formula structural formula. 

The language of chemistry is understood better when the symbols of the more common elements are known, such as those shown on the following page. Use of these symbols provides a convenient shorthand method for chemists to represent molecular formulae. In these formulae, the subscript number following the atomic symbol denotes how many atoms of that element are in the molecule, for example, the formula for water is H2O, which means each molecule of water contains two atoms of hydrogen (symbol H) and one atom of oxygen (symbol O). 

Carbon, a common element in the outer crust of the earth, and the main component of all biological and organic substances, occurs in three isotopic forms carbon-12 or C-12 for short (whose chemical symbol is 12C), carbon-13 or C-13 (13C), and carbon-14 or C-14 (14C) (see Fig. 8 and Table 66). 

Two of these isotopes, carbon-12, the most abundant, and carbon-13 are stable. Carbon-14, on the other hand, is an unstable radioactive isotope, also known as radiocarbon, which decays by the beta decay process a beta particle is emitted from the decaying atomic nucleus and the carbon-14 atom is transformed into an isotope of another element, nitrogen-14, N-14 for short (chemical symbol 14N), the most common isotope of nitrogen ... 

In metals the electrons lose their association with individual atoms and the number of valence electrons is often used in rationalization schemes. Estimated enthalpies of formation for equi-atomic alloys, MM, of two elements of the first transition metal series are given as a function of the difference in number of valence electrons in Figure 7.13 [8], Compounds of a given common metal are given a specific symbol. For example, the scandium compounds ScM where M = Ti, V, Cr, Mn, Fe, Co, Ni and Zn, are given by open circles. The metal M of the compound MM is... 

Each square on this table represents a different element and contains three bits of information. The first is the element symbol. You should become familiar with the symbols of the commonly used elements. Secondly, the square fists the atomic number of the element, usually centered above the element. This integer represents the number of protons in the element s nucleus. The atomic number will always be a whole number. Thirdly, the square fists the elements mass, normally centered underneath the element symbol. This number is not a whole number because it is the weighted average (taking into consideration abundance) of all the masses of the naturally occurring isotopes of that element. The mass number can never be less than the atomic number. 

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