Dot Symbols

Electron-dot symbols for the first eighteen elements. This scheme, invented in the early twentieth century by G. N. Lewis, provides a rough but useful tool for predicting the availability of an atom s valence electrons for chemical bonding. 

EXAMPLE 3.14. Write the electron dot symbols for the elements Li through Ne. 

Write the electron dot symbol for each atom in Problem 3.25. 

The Lewis electron-dot symbol is a way of representing the element and its valence electrons. The chemical symbol is written, which represents the atom s nucleus and all inner-shell electrons. The valence, or outer-shell, electrons are represented as dots surrounding the atom s symbol. Take the valence electrons, distribute them as dots one at a time around the four sides of the symbol and then pair them up until all the valence electrons are distributed Figure 11.1 shows the Lewis symbol for several different elements. 

Figure 11.1 Lewis electron-dot symbols for selected elements.

Electrons in the outermost occupied shell of any atom may play a significant role in that atoms chemical properties, including its ability to form chemical bonds. To indicate their importance, these electrons are called valence electrons (from the Latin valentia, strength ), and the shell they occupy is called the valence shell. Valence electrons can be conveniently represented as a series of dots surrounding an atomic symbol. This notation is called an electron-dot structure or, sometimes, a Lewis dot symbol, in honor of the American chemist G. N. Lewis, who first proposed the concepts of shells and valence electrons. Figure 6.2 shows the electron-dot structures for the atoms important in our discussions of ionic and covalent bonds. (Atoms of elements in groups 3 through 12 form metallic bonds, which we ll study in Chapter 18.)... 

Lewis Symbol or Electron Dot Symbol Such a symbol marks the number of electrons in the outermost shell of the element around the symbol of the element , e.g. 

Lewis symbols, or electron dot symbols, are useful ways to represent the valence electrons in many elements. 

The electron-dot symbols of these atoms are usually drawn by showing only the electrons of the outer shell. These symbols for the atoms lithium to neon are accordingly the following ... 

Lewis structures (also called electron-dot structures) are formed when Lewis symbols (also called electron-dot symbols) are combined. Lewis symbols are a simple way of visualizing the valence electrons in an atom, hi a Lewis symbol, the symbol for the element is used to represent the atom and its core electrons. Dots placed around the atom are used to indicate the valence electrons. When combined to form Lewis structures, Lewis symbols make it possible to predict the shape of many molecules and ions. This information is particularly useful as many physical and chemical properties of molecules and ions are dependent on their shape. 

The American chemist G. N. Lewis introduced a useful model that describes the electronic structure of the atom and provides a starting point for describing chemical bonds. The Lewis model represents the valence electrons as dots arranged around the chemical symbol for the atom the core electrons are not shown. The first four dots are displayed singly around the four sides of the elemental symbol. If the atom has more than four valence electrons, their dots are then paired with those already present. The result is a Lewis dot symbol for that atom. The Lewis notation for the elements of the first two periods is... 

Describe the shell structure of the atom, and represent valence shell electrons of an atom by its Lewis electron dot symbol (Section 3.3, Problems 11 and 12). 

FIGURE 11.6 Calculated DO VS of cumulene chain without kinks (a) and with periodical kinks (.55°), dotted symbol experiment. 

Fig. 3. Nonexponential curve fitting based upon fluorescence data convolutions in Figures la and 1b, respectively. Fig. 3a dots (symbol o), experimental (artificial) pattern, according to Equation I smooth solid curve (----), preliminary fit to Equation 6 with...

For each of the following elements, tell how many electrons are in each energy level and then write the Lewis dot symbol for each atom. 

The valence electrons for an element can be depicted visually in an electron-dot symbol. (Electron-dot symbols are known by other names, including electron-dot structures, electron-dot diagrams, and Lewis electron-dot symbols.) An electron-dot symbol that shows chlorine s seven valence electrons is... 

Electron-dot symbols are derived by placing valence electrons (represented by dots) to the right, left, top, and bottom of the element s symbol. Starting on any of these four sides, we place one dot at a time until there are up to four unpaired electrons around the symbol. If there are more than four valence electrons for an atom, the remaining electrons are added one by one to the unpaired electrons to form up to four pairs. 

There is no set convention for the placement of the paired and unpaired electrons around the symbol. For example, the electron-dot symbol for chlorine atoms could be... 

Like chlorine, the other elements in group 7A also have seven valence electrons, so their electron-dot symbols are similar to that of chlorine. The unpaired dot can be placed on any of the four sides of each symbol. 

Objective 11 Carbon, in group 4A, has four unpaired electrons in its electron-dot symbol. 

Table 3.1 shows electron-dot symbols for the nonmetallic atoms and lists their most common bonding patterns. Note that the sum of the numbers of bonds and lone pairs is always four for the elements in this table. 

Electron-Dot Symbols and Usual Numbers of Bonds and Lone Pairs for Nonmetallic Elements... 

Electron-dot symbol A representation of an atom that consists of its elemental symbol surrounded by dots representing its valence electrons. 

Draw electron-dot symbols for the nonmetallic elements and use them to explain why these elements form the bonding patterns listed in Table 3.1. 

Write or identify the definitions of valence electrons, electron-dot symbol, lone pairs. 

To visuali2 this process, we can use the electron-dot symbols introduced in Chapter... 

The electron-dot symbol or electron-dot structure of an element shows the valence electrons as dots. Electrons that are paired in an orbital are shown as a pair of dots, and unpaired electrons are shown as single dots. The paired valence electrons are called lone pairs (because they do not participate in bonding). In an electron-dot symbol, the lone pairs and the single dots are arranged to the right, left, top, and bottom of the element s symbol. The electron-dot symbol for fluorine can be drawn with the single dot in any of the four positions ... 

Usually, the covalent bonds in the electron-dot symbols for molecules are indicated... 

Each hydrogen atom in its ground state has one valence electron in a Is orbital. Its electron-dot symbol is therefore... 

The following describes the bond formation in methane using electron-dot symbols. 

Nitrogen is in group 5A, so it has five valence electrons. Its orbital diagram and electron-dot symbol are... 

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