Electron dot structure

It is very common in chemistry to draw structures of chemical compounds using dots or dashes to coimect atoms together. A single dot represents one electron, and a pair of dots represents a pair of electrons. A dash also represents a pair of electrons. Either way, a pair of electrons connecting two atoms is our usual representation of a chemical bond. 

The University of CaUfornia physical chemist Gilbert Newton Lewis (1875-1946) introduced a notation to represent atoms and their valence (outermost) electrons that today we call Lewis electron dot structures in his honor. Here are the dot structures for first ten elements in the periodic table  

Elements in the same column as one of the above elements have analogous electron dot structures. For example, silicon s structure is Si. An important feature of Lewis s symbols for atoms is that the number of unpaired electrons in the symbol is usually the number of chemical bonds that element will form. Thus, a hydrogen atom can form only one bond. 

An oxygen atom can form two bonds, a nitrogen atom three bonds, and a carbon atom four bonds. 

We can combine Lewis structures for atoms to make Lewis structures for molecules.  

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Draw an electron-dot structure for acetonitrile, C2H3N, which contains a carbon-nitrogen triple bond. How many electrons does the nitrogen atom have in its outer shell How many are bonding, and how many are non-bonding ... 

Complete the electron-dot structure of caffeine, showing all lone-pair electrons, and identify the hybridization of the indicated atoms. 

Draw an electron-dot structure for each of the molecules in Problem 2.38, indicating any unshared electron pairs. 

Reaction of iodoethane with CN yields a small amount of isonitrile, CH3CH2N = C, along with the nitrile CH CE C N as the major product. Write electron-dot structures for both products, assign formal charges as necessary, and propose mechanisms to account for their formation. 

Electron-dot structure (Section 1.4) A representation of a molecule showing valence electrons as dots. 

Electron movement, curved arrows and, 44-45, 57-58 Electron shell, 5 Electron-dot structure, 9 Electron-transport chain, 1127 Electronegativity, 36... 

In 1923. Lewis published a classic book (later reprinted by Dover Publications) titled Valence and the Structure of Atoms and Molecules. Here, in Lewis s characteristically lucid style, we find many of the basic principles of covalent bonding discussed in this chapter. Included are electron-dot structures, the octet rule, and the concept of electronegativity. Here too is the Lewis definition of acids and bases (Chapter 15). That same year, Lewis published with Merle Randall a text called Thermodynamics and the Free Energy of Chemical Substances. Today, a revised edition of that text is still used in graduate courses in chemistry. 

Draw electron dot structures for each of the following molecules (a) CO, (b) C02, (c) HCN, (d) N20 (an unsymmetrical molecule, with the two nitrogen atoms adjacent to each other). 

The products are determined first (from electron dot structures, if necessary) to be NaCl, MgO, and Li,S, respectively. These are placed to the right of the respective arrows, and the equations are then balanced. 

With the information given in Table 21-1, it is possible to write an electron dot structure for an organic molecule. 

Electron dot structures are not usually written for transition metal or inner transition metal atoms. They do lose electrons, forming ions. If you are asked to draw an electron dot diagram for a compound containing a monatomic transition metal ion, show the ion with no outermost electrons. 

The charges on polyatomic ions cause ionic bonding between these groups of atoms and oppositely charged ions. In writing electron dot structures, the distinction between ionic and covalent bonds must be clearly indicated. For example, an electron dot diagram for the compound NH4NO, would be... 

Explain the bond structure of the BC13 molecule by using electron dot structure. 

Show the bond structure of the nitrogen molecule by using an orbital diagram, electron dot structure and line representation. 

FIGURE 5.16 The electron dot structure of a nitrogen atom (left) and an ammonia molecule (right). The pair of electrons above the nitrogen is the nonbonding pair available for coordinate covalent bonding. 

B—The Lewis (electron-dot) structure has five bonding pairs around the central Sb and no lone pairs. VSEPR predicts this number of pairs to give a trigonal bipyramidal structure. 

The Lewis electron-dot structure is a way of representing an element and its valence electrons. 

To determine the electron dot structure of any element, count the number of electrons in that element s valence shell. Then draw that number of dots around the chemical symbol for the element. To do so, imagine the chemical symbol as a square. Start from the top of the symbol and, going clockwise, put one dot on each side until you run out of valence electrons. Don t double up on any side until you ve gone around the square once. 

Electron dot structures for elements in the first two rows of the periodic table. 

Draw the electron dot structure of potassium fluoride and show how the electron is transferred between the elements potassium and fluorine to create the ionic compound. 

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