Electron-dot notation

To represent the formation of bonds between atoms, it is convenient to use a system known as electron dot notation. In this notation, the symbol for an element is used to represent the nucleus of an atom of the element plus all the electrons except those in the outermost (valence) shell. The outermost electrons are represented by dots (or tiny circles or crosses). For example, the dot notations for the first 10 elements in the periodic table are as follows  

Using electron dot notation, the production of sodium fluoride, calcium fluoride, and calcium oxide may be pictured as follows A sodium atom and a fluorine atom react in a 1 1 ratio, since sodium has one electron to lose from its outermost shell and fluorine requires one more electron to complete its outermost shell. 

To lose its entire outermost shell, a calcium atom must lose two electrons. Since each fluorine atom needs only one electron to complete its octet, it takes two fluorine atoms to react with one calcium atom  

The calcium atom has two electrons in its outermost shell. Each oxygen atom has six electrons in its outermost shell and requires two more electrons to attain its octet. Each oxygen atom therefore requires one calcium atom from which to obtain the two electrons, and calcium and oxygen react in a 1 1 ratio. 

EXAM PLE 5.6. With the aid of the periodic table, use electron dot notation to determine the formula of the ionic compound formed between lithium and oxygen. 

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The covalent bonding in organic compounds can be described by means of the electron dot notation (Chap. 5). The carbon atoms has four electrons in its outermost shell ... 

The formation of covalent bonds between atoms can be conventionally depicted by means of the electron dot notation. The formation of some covalent bonds is shown in this manner below ... 

Have you ever wondered how to draw the structures of compounds For example, compounds such as CCI4, PBr3 or ions such as SO. To draw the structural formulae we will use the Lewis (electron dot) notation. 

While chemical bonds are represented by lines connecting atoms, electron dot notation is commonly used to represent lone pairs (nonbonding pairs) of electrons. Lone pairs are found on heteroatoms (atoms other than carbon or hydrogen) that do not require bonds with additional atoms to fill their valence shell of eight electrons. For example, atomic... 

Explain why uncombined atoms of all the elements in a given main group of the periodic table will be represented by a similar electron dot notation. 

Which element could have the ground-state electron-dot notation shown in Figure 5.26 ... 

Reflect and t ply Using the Lewis electron-dot notation, show explicitly the transfer of electrons in the following redox reactions. 

Chemists use a number of different methods to represent chemical bonds. In Chap. 2 we introduced the concept of electron dot notation to represent the structure of the valence shells of the elements of Period 2 of the Periodic Table. These were... 

We can also use electron dot notation to show how we can determine the composition (formula) of the ionic compound formed, for example, between calcium and chlorine. The valence electrons of the atoms can be determined by noting that calcium is in Group II and chlorine is in Group VII of the Periodic Table. Calcium therefore has two, and chlorine seven, valence electrons. It requires two chlorine atoms to accept the two valence electrons from calcium ... 

Writing Electron-Dot Notations lo write an element s electron-dot notation, determine the element s number of valence electrons. Then place a corresponding number of dots around the element s symbol, as shown. ... 

Number of valence electrons Electron-dot notation Example... 

Covalent bond formation usually involves only the electrons in an atom s outermost energy levels, or the atom s valence electrons. To keep track of these electrons, it is helpM to use electron-dot notation. Electron-dot notation is an eiectron-conflguration notation in which oniy the vaience eiectrons of an atom of a particular element are shown, indicated by dots placed around the element s symbol. The inner-shell electrons are not shown. For example, the electron-dot notation for a fluorine atom (electron configuration [He]2s 2p ) may he written as follows. 

In general, an element s number of valence electrons can be determined by adding the superscripts of the element s noble-gas notation. In this hook, the electron-dot notations for elements with 1-8 valence electrons are written as shown in Figure 2.8. 

Electron-dot notation can also be used to represent molecules. For example, a hydrogen molecule, is represented by combining the... 

The pair of dots represents the shared electron pair of the hydrogen-hydrogen covalent bond. For a molecule of fluorine, F2, the electron-dot notations of two fluorine atoms are combined. 

SOLVE 1. Determine the type and number of atoms in the molecule. The formula shows one carbon atom, one iodine atom, and three hydrogen atoms. 2. Write the electron-dot notation for each type of atom in the molecule. Carbon is from Group 14 and has four valence electrons. Iodine is from Group 17 and has seven valence electrons. Hydrogen has one valence electron. 

Write the electron-dot notation for each type of atom. 

Electron-dot notation can be used to demonstrate the changes that take place in ionic bonding. Ionic compounds do not ordinarily form by the combination of isolated ions, but consider for a moment a sodium atom and a chlorine atom approaching each other. The two atoms are neutral and have one and seven valence electrons, respectively. 

Use electron-dot notation to demonstrate the formation of ionic compounds involving the following ... 

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