Examples of Covalent Bonding

7 Key excerpts on "Examples of Covalent Bonding"

• 

  eBook - PDF

  Introduction to Molecular Science

  • Ageetha Vanamudan(Author)
  • 2023(Publication Date)
  • Delve Publishing

    (Publisher)

  Source: By DynaBlast - Created with Inkscape, CC BY-SA 2.5, https://com- mons.wikimedia.org/w/index.php?curid=995735 Covalent Bonding 115 7.1 DO YOU UNDERSTAND WHY COVALENT BONDS FORM? When the difference in electronegativity between two atoms is insufficient for electron transit, a covalent bond is created. Electronegativity is a measure of an atom’s capacity to attract electrons. Atoms create covalent bonds to strengthen their stability by forming a whole electron shell by sharing their outermost (valence) electrons.The attraction between positively charged nuclei and shared electrons is stronger than the repulsion between them in covalent bonds. This attraction aids in the retention of the molecules. The amount of energy required to break the connection, or the amount of energy required to separate the connected atoms determines the strength of a covalent bond. Figure 7.2: Structure of the covalent bonding of methane. Source: By Original: Benjah-bmm27 Vector: Jynto - Own work based on: File:Methane-CRC-MW-dimensions-2D.png, Public Domain, https://com- mons.wikimedia.org/w/index.php?curid=12422898 7.2 COVALENT BOND CHARACTERISTICS In the structure of stable covalent compounds, covalent bonding is typically the controlling factor. A covalent bond has the following characteristics and qualities: • It is possible to make multiple covalent bonds between two atoms when composed of two or more nonmetals, or one nonmetal and a metalloid. Breaking bonds requires a lot of energy, which is why it is so tough (Krylov & Gill, 2013). Directional or Isomerism is the phenomenon in which one chemical formula may represent several distinct molecules. Introduction to Molecular Science 116 • Covalent compounds have low melting and boiling temperatures, do not conduct electricity, and are insoluble in polar solvents such as water. Covalent substances can be dissolved using nonpolar solvents such as benzene and toluene.

  Sign up to read

  Learn more about book
• 

  eBook - PDF

  General Chemistry: Atoms First

  • Young, William Vining, Roberta Day, Beatrice Botch(Authors)
  • 2017(Publication Date)
  • Cengage Learning EMEA

    (Publisher)

  6 Covalent Bonding Unit Outline 6.1 Covalent Bonding and Lewis Structures 6.2 Properties of Covalent Bonds 6.3 Resonance and Bond Properties In This Unit… We will examine chemical bonding in detail in this unit and the next. Here we apply what you have learned about atomic structure, elec-tron configurations, and periodic trends to the chemical bonds formed between atoms. This unit and the next primarily address covalent bond-ing; we examined ionic bonding briefly in Ionic and Covalent Compounds (Unit 5), and we will do so in more detail in The Solid State (Unit 13). We will also examine the forces that exist between individual particles, called intermolecular forces, in Intermolecular Forces and the Liquid State (Unit 12). Vasilyev/Shutterstock.com Copyright 2018 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. WCN 02-300 Unit 6 Covalent Bonding 132 6.1 Covalent Bonding and Lewis Structures 6.1a Fundamentals of Covalent Bonding A covalent bond is characterized by the sharing of valence electrons by two adjacent atoms. This type of bonding occurs most typically between nonmetal elements such as carbon, hydrogen, oxygen, and nitrogen. For example, consider a simple covalently bonded molecule, H 2 (Interactive Figure 6.1.1). When two isolated H atoms are at a great distance from one another, they feel no attractive or repulsive forces. However, as the atoms approach more closely, the attractive and repulsive forces between the two atoms become important. At very short dis-tances, repulsive forces become more important than attractive forces, and the atoms repel. Attractive forces between the hydrogen atoms result from the interaction between the positively charged nucleus (represented by the element symbol) on one hydrogen atom and the negatively charged electron (represented by a dot) on the other hydrogen atom.

  Sign up to read

  Learn more about book
• 

  eBook - PDF

  Chemistry for the Life Sciences

  • Raul Sutton(Author)
  • 2008(Publication Date)
  • CRC Press

    (Publisher)

  15 Covalent Bonding and Molecules 2.1 Introduction A liing organism deries most of its character from the enormous range of molecules contained within it. These help to determine the structure of the body, the function of enzymes, the clotting of blood, cell respira-tion, and innumerable other features. It is useful for us to understand the structure of molecules and to consider the properties they show in order to interpret the role they perform in the organism. 2.2 Interactions between Atoms Proteins, sugars, and other important biological molecules are collec-tions of atoms held together by a force of attraction called covalent bonding . Coalent bonds are formed between atoms that can share electrons to achiee a full shell of electrons. Such a full shell is a ery stable structure. When two atoms moe toward one another, the outer-shell electrons in each rearrange themseles to reduce their poten-tial energy. The energy falls to a minimum when they are a specific distance apart. This distance, when measured between the two atomic nuclei, is called the bond length . The fall in energy that has occurred is the bond energy (Figure 2.1). Atoms share electrons to form covalent bonds. Atoms share electrons to form covalent bonds. 2 Potential Energy + – 0 r E Distance between Nuclei Figure 2.1 Potential energy change which occurs when two atoms are brought together to form a chemical bond. The fall in energy E corresponds to the energy of the chemical bond. The distance r between the nuclei of the two atoms represents the potential energy minimum and is the bond length. 16 Chemistry for Life Sciences 2.3 Covalent Bonds Are Formed by Sharing Outer Electrons The simplest way to describe the formation of a coalent bond is to consider the way in which the outer shells of electrons in the atoms interact as the atoms approach one another. The outer shell of electrons is often called the alence shell, so this description of coalent bond-ing is called the valence-bond theory .

  Sign up to read

  Learn more about book
• 

  eBook - PDF

  Chemistry

  An Atoms First Approach

  • Steven Zumdahl, Susan Zumdahl, Donald J. DeCoste, , Steven Zumdahl, Steven Zumdahl, Susan Zumdahl, Donald J. DeCoste(Authors)
  • 2020(Publication Date)
  • Cengage Learning EMEA

    (Publisher)

  During the twentieth century we learned that atoms have electrons and that these electrons participate in bonding one atom to another. ▲ Quartz grows in beautiful, regular crystals. 99 Copyright 2021 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it. The forces that hold atoms together in compounds are called chemical bonds. One way that atoms can form bonds is by sharing electrons. These bonds are called cova- lent bonds, and the resulting collection of atoms is called a molecule. Molecules can be represented in several different ways. The simplest method is the chemical formula, in which the symbols for the elements are used to indicate the types of atoms present and subscripts are used to indicate the relative numbers of atoms. For example, the formula for carbon dioxide is CO 2 , meaning that each molecule contains 1 atom of carbon and 2 atoms of oxygen. Examples of molecules that contain covalent bonds are hydrogen (H 2 ), water (H 2 O), oxygen (O 2 ), ammonia (NH 3 ), and methane (CH 4 ). More information about a molecule is given by its structural formula, in which the individual bonds are shown (indicated by lines). Structural formulas may or may not indicate the actual shape of the mole- cule. For example, water might be represented as H O H H H O or The structure on the right shows the actual shape of the water molecule. Scientists know from experimental evidence that the molecule looks like this. (We will study the shapes of molecules further in Chapter 4.) The structural formula for ammonia is Ammonia H H H N .

  Sign up to read

  Learn more about book
• 

  eBook - PDF

  Chemistry

  The Molecular Nature of Matter

  • Neil D. Jespersen, Alison Hyslop(Authors)
  • 2014(Publication Date)
  • Wiley

    (Publisher)

  Practice Exercise 8.7 Practice Exercise 8.8 364 Chapter 8 | The Basics of Chemical Bonding 8.5 | Covalent Bonds Most of the substances we encounter in our daily lives are not ionic. Instead, they are composed of electrically neutral molecules. The chemical bonds that bind the atoms to each other in such molecules are electrical in nature, but arise from the sharing of electrons rather than by electron transfer. Energy Changes on Bond Formation In Section 8.2 we saw that for ionic bonding to occur, the energy-lowering effect of the lattice energy must be greater than the combined net energy-raising effects of the forma- tion of gaseous atoms, ionization energy (IE), and electron affinity (EA). Many times this is not possible. For example, nonmetals, which often have large ionization energies, com- bine together to form molecules. In such cases, nature uses a different way to lower the energy—electron sharing. Let’s look at what happens when two hydrogen atoms join to form a hydrogen mole- cule (Figure 8.6). As the two atoms approach each other, the electron of each atom begins to feel the attraction of both nuclei. This causes the electron density around each nucleus to shift toward the region between the two atoms. Therefore, as the distance between the nuclei decreases, there is an increase in the probability of finding either electron near either nucleus. In effect, as the molecule is formed, each of the hydrogen atoms in the H 2 mol- ecule shares the two electrons. In the H 2 molecule, while the buildup of electron density between the two atoms attracts both nuclei and pulls them together, the two nuclei also repel each other, as they are the same charge. In the molecule that forms, therefore, the atoms are held at a distance at which all these attractions and repulsions are balanced. Overall, the nuclei are kept from separating, and the net force of attraction produced by sharing the pair of electrons is called a covalent bond.

  Sign up to read

  Learn more about book
• 

  eBook - PDF

  Principles of Inorganic Chemistry

  • Brian W. Pfennig(Author)
  • 2021(Publication Date)
  • Wiley

    (Publisher)

  4 An Introduction to Chemical Bonding “A bond does not really exist at all—it is a most convenient fiction.” —Charles Coulson 4.1 THE DEFINITION OF A CHEMICAL BOND Almost every chemical reaction involves the making and/or breaking of a chemical bond. Despite its central importance in the lexicon of chemistry, there continues to be a healthy debate about what a bond actually is, so much so that the British theoretician, Charles Coulson, once quipped that “a bond does not really exist at all—it is a most convenient fiction.” Suppose that I asked my students for their definition of a chemical bond. I imagine that many of them might turn to the fountain of all knowledge known as Wikipedia for a definition. Going straight to the source myself, Wikipedia defines a chemical bond as “a lasting attraction between atoms that enables the formation of a chemical compound,” a circular argument if ever there was one. The Collins English dic- tionary has only a slightly better answer, defining a bond as “a mutual attraction between two atoms resulting from a redistribution of their outer electrons.” Dissatisfied with either of these definitions, I thought I would turn to the OG himself—Gilbert Newton Lewis, who is arguably the godfather of the chemical bond.

  Sign up to read

  Learn more about book
• 

  eBook - PDF

  Chemistry

  Structure and Dynamics

  • James N. Spencer, George M. Bodner, Lyman H. Rickard(Authors)
  • 2011(Publication Date)
  • Wiley

    (Publisher)

  These compounds are called ionic compounds, which are discussed in Chapter 5. NaCl, for example, is an ionic compound in which most of the electron density in the bond is transferred from the sodium atom to the more electronegative chlorine atom. In the covalent molecules discussed so far in this chapter, the electrons in the covalent bonds are shared more or less evenly between bonding atoms. If the atoms in a bond have significantly different electronegativities, the more elec- tronegative atom will attract more of the electron density in the bond. This type of bond is referred to as a polar covalent bond. One end of the bond has a par- tial positive charge (), and the other end has a partial negative charge (). 140 CHAPTER 4 / THE COVALENT BOND Fig. 4.8 (a) Electronegativities of the elements calculated from photoelectron spectroscopy and refined AVEE. The AVEE data from Chapter 3 have been adjusted to give fluorine an electronegativity value close to 4. [Reprinted from L. C. Allen and E. T. Knight, Journal of Molecular Structure, 261, 313 (1992).] (b) Electronegativities based on the Pauling scale. K 0.73 Ca 1.03 Na 0.87 Mg 1.29 Li 0.91 H 2.30 Be 1.58 Sc 1.2 Ti 1.3 V 1.4 Cr 1.5 Mn 1.6 Fe 1.7 Co 1.8 Ni 1.9 Cu 1.8 Zn 1.6 Ga 1.76 Ge 1.99 As 2.21 Se 2.42 Kr 2.97 Al 1.61 Si 1.92 P 2.25 S 2.59 Ar 3.24 B 2.05 C 2.54 N 3.07 O 3.61 Ne 4.79 He 4.16 H 2.30 Rb 0.71 Sr 0.96 Y 1.0 Zr 1.1 Nb 1.3 Mo 1.4 Tc 1.5 Ru 1.7 Rh 1.8 Pd 1.9 Ag 2.0 Cd 1.5 In 1.66 Sn 1.82 Sb 1.98 Te 2.16 Xe 2.58 Cs 0.66 Ba 0.88 Hg 1.76 (a ) AVEE Scale Br 2.69 Cl 2.87 F 4.19 I 2.36 K 0.8 Ca 1.0 Na 0.9 Mg 1.2 Li 1.0 H 2.1 Be 1.5 Sc 1.3 Ti 1.5 V 1.6 Cr 1.6 Mn 1.5 Fe 1.8 Co 1.9 Ni 1.9 Cu 1.9 Zn 1.6 Ga 1.6 Ge 1.8 As 2.0 Se 2.4 Kr – Al 1.5 Si 1.8 P 2.1 S 2.5 Ar – B 2.0 C 2.5 N 3.0 O 3.5 Ne – He – H 2.1 Rb 0.8 Sr 1.0 Y 1.2 Zr 1.4 Nb 1.6 Mo 1.8 Tc 1.9 Ru 2.2 Rh 2.2 Pd 2.2 Ag 1.9 Cd 1.7 In 1.7 Sn 1.8 Sb 1.9 Te 2.1 Xe – Cs 0.7 Ba 0.9 Hg 1.9 (b) Pauling Scale Br 2.8 Cl 3.0 F 4.0 I 2.5 Fig.

  Sign up to read

  Learn more about book