Symbol of an element

Lewis symbol (for atoms and ions) The chemical symbol of an element, with a dot for each valence electron. 

The symbol of an element must match its atomic number. Verily this for uranium and carbon by consulting a periodic table. The superscript must be larger than the subscript, since the superscript is the sum of the number of protons (the subscript) and the number of neutrons. 

The smallest particle of an element that retains the composition of the element is called an atom. Details of the nature of atoms are given in Chaps. 3 and 17. The symbol of an element is used to stand for one atom of the element as well as for the element itself. 

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. ... 

To balance an equation, you use coefficients to alter the number of moles of reactants and/or products so the mass on one side of the equation equals the mass on the other side. A coefficient is simply a number that precedes the symbol of an element or compound, multiplying the number of moles of that entire compound within the equation. Coefficients are different from subscripts, which multiply the number of atoms or groups within a compound. Consider the following ... 

Special attention is also given to the description of names of metal-cyclic structures [28]. If a group of simultaneously coordinated atoms of the chelating ligand is present in the complex, the symbols of all atoms and groups are enumerated, separated by a comma, after the symbol Q followed by a An upper index number on the right of the symbol of an element indicates its number within the group. 

A list of ACS-recommended abbreviations, acronyms, and symbols is given in Appendix 10-2. Check the list to find an abbreviation. If no abbreviation is listed for the term you are using, you may devise an abbreviation provided that (1) it is not identical to an abbreviation of a unit of measure, (2) it will not be confused with the symbol of an element or a group, (3) it does not hamper the reader s understanding, and (4) you do not use the same abbreviation for more than one spelled-out form. 

Here, X represents any symbol of an element such as Al, K, Mg etc... Now, let s see an example. A neutral sodium atom (Na) has 11 protons, 11 electrons, 12 neutrons, and an atomic mass number of 23, which are shown thusly ... 

When the elemental symbol of an element is combined with additional information, such as the atomic number, mass number, or charge, it is usually called elemental notation. Elemental notation is a simple way of summarizing a good deal of information in a small space. 

The asterisk ( ) is used in formulae as a right superscript to the symbol of an element, in the following ways ... 

In a formula, the main symbols indicate the species present at a certain site, defined with respect to empty space. This will generally be the symbol of an element. If a site is vacant this is denoted by the italicized symbol V. (In certain contexts other symbols, such as a square box, , are used for vacancies, but the use of italicized V is preferred, the element vanadium being written with the upright letter V). 

Symbol (of an element) A letter or group of letters that represents (identifies) an element. 

The chemical formula for a substance shows its chemical composition. This represents the elements present as well as the ratio in which the atoms of the elements occur. The formula for a single atom is the same as the symbol for the element. Thus, Na can represent a single sodium atom. It is unusual to find such isolated atoms in nature, with the exception of the noble gases (He, Ne, Ar, Kr, Xe, and Rn). A subscript following the symbol of an element indicates the number of atoms in a molecule. For instance, F2 indicates a molecule containing two fluorine atoms, and a molecule containing four phosphorus atoms. 

Because valence electrons are so important to the behavior of an atom, it is useful to represent them with symbols. A Lewis dot diagram illustrates valence electrons as dots (or other small symbols) aroimd the chemical symbol of an element. Each dot represents one valence electron. In the dot diagram, the element s symbol represents the core of the atom—the nucleus plus aU the inner electrons. The Lewis dot diagrams for several elements are shown in Figure 2.26. 

Lewis dot diagram a diagram where dots or other small symbols are placed around the chemical symbol of an element to illustrate the valence electrons. (Chap. 2, p. 79)... 

Lewis dot symbol. The symbol of an element with one or more dots that represent the number of valence electrons in an atom of the element. (9.1)... 

Main symbol. The main symbol is either the species involved, i.e.. chemical symbol of an element, or the letter V for vacancy. 

The symbol of an element, standing alone, signifies 1 atom, or equivalent, of the element. Thus O stands for 1 atom of oxygen, H for 1 atom of hydrogen, and Fe for 1 atom of iron (femim). 

If the chemical formula is the chemical symbol of an element, such as Na, the formula weight equals the atomic weight of the element, in this case 23.0 amu. If the chemical formula is that of a molecule, the formula weight is also called the molecular weight. The molecular weight of glucose (CgHi20g), for example, is... 

Lewis structure of an atom The symbol of an element surrounded by a number of dots equal to the number of electrons in the valence shell of the atom. 

It is useful to have some simple way of showing the hydrogen atom s single electron in chemical symbols and formulas. This is accomplished with electron-dot symbols or Lewis symbols (after G. N. Lewis), which use dots around the symbol of an element to show outer electrons (those that may become involved in chemical bonds). The Lewis symbol for hydrogen is... 

When atoms interact to form a chemical bond, only their outer regions are in contact. For this reason, when we study chemical bonding, we are concerned primarily with the valence electrons of the atoms. To keep track of valence electfons in a chemical reaction, chemists use a system of dots devised by Lewis called the Lewis dot symbols. A Lewis dot symbol consists of the symbol of an element and one dot for each valence electron in an atom of the element. Figure 3.3 shows the Lewis dot symbols for the representative elements and the noble gases. 

A symbol is used to represent an atom of an element, as well as the element itself. The symbol I represents the element iodine, and also may be used to mean the elementary substance. However I2 is the customary formula for the elementary substance, because it is known that elementary iodine consists of molecules containing two atoms in the solid and liquid states as well as in the gaseous state (except at very high temperature). In formulas showing composition or molecular structure the numerical subscript of the symbol of an element gives the number of atoms of the element in the molecule. 

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