1. Ionic And Covalent Bonding Study Guide Answers

Mom always said that sharing is caring. This lesson will explore how electrons affect the chemical reactivity of atoms and specifically the merits of sharing electrons. Identify covalent or ionic compounds and predict their formula using valence. Predict whether these atoms will form a covalent or ionic compound together, then predict the formula of their compound: a) i) Mg and O ii) C and O. B) i) P and Cl ii) Na and F. Ionic and covalent bonding. When an atom bonds to another atom, it is trying to fill its. What happens during ionic bonding? How are ionic bonds held together? Ionic bonds are.

All other chemical elements need to lose or gain electrons to achieve electronic stability. Table 1 shows the stable electron configurations for the elements in the first three rows of the periodic table. Most atoms achieve a stable number of valence electrons by sharing electrons with other atoms. Begin with fluorine, element 9, which has the electron configuration 1 s 2 2 s 2 2 p 5. The orbitals of the valance electron shell are 2 s 2 p, with two electrons in the 2 s and five electrons in the 2 p. These seven valence electrons can be portrayed in a diagram devised by the American chemist Gilbert Lewis (1875–1946).

In Figure 1, a Lewis diagram shows each valence electron as a single dot. Figure 1. The valence electrons. In Figure 2, two fluorine atoms can each fill their valence orbitals with eight electrons if they approach each other to share their single electrons. Figure 2. Fluorine atoms sharing two electrons. Count the electrons in the Lewis diagram; notice that there are 14 electrons, with each atom contributing 7. The two fluorine atoms form a stable F 2 molecule by sharing two electrons; this linkage is called a covalent bond. You can determine the number of valence electrons for the light elements by counting the columns from the left.

(See Figure 3.) Figure 3. Counting valence electrons. Phosphorus has five valence electrons, and chlorine has seven, so their isolated atoms have Lewis configurations as shown in Figure 4. Figure 4. The valence electrons of phosphorus and chlorine. Phosphorus must combine with three chlorines to complete its valence shell. (See Figure 5.) Figure 5. Six electrons shared between phosphorus and chlorine. Study Figure carefully. First, see that each atom is now surrounded by a full shell of eight valence electrons.

Of the 26 valence electrons, 6 are shared, and 20 are unshared. For the six that are shared to form the covalent bonds, the phosphorus atom contributed three, and each of the chlorines contributed one. The resulting PCl 3 molecule is usually drawn as shown in Figure 6. Figure 6. Three covalent bonds. Each of the three lines represents the shared pair of electrons in a covalent bond.

When lines are used to represent bonding pairs of electrons, the structure is often called a structural formula. Some textbooks omit the nonbonding electrons for simplicity.

Because the hydrogen atom has its single 1 s orbital completed with only two electrons, the hydrogen chloride molecule is drawn as shown in Figure 7. Figure 7. The hydrogen chloride molecule. The The hydrogen and chlorine atoms each donate one electron to the covalent bond.

In the molecule, the hydrogen has completed its valence shell with two electrons, and the chlorine has a full shell with eight valence electrons. In some molecules, bonded atoms share more than two electrons, as in ethylene (C 2H 4), where the two carbons share four electrons. (See Figure 8.) Figure 8. A double bond between two carbon atoms. Notice that each carbon achieves eight electrons by this sharing. Because each shared pair constitutes a single covalent bond, the two shared pairs are called a double bond. The structure on the right side of Figure 8 shows this double bond of four shared electrons with two lines, and the left side of Figure shows the double bond as two pairs of dots.

There are even triple bonds of six shared electrons, as in the nitrogen molecule. In N 2, each nitrogen atom contributes five valence electrons. Of the 10 electrons shown in Figure 9, four are nonbonding, and six comprise the triple bond holding the nitrogen atoms together. Figure 9. A triple bond between two nitrogen atoms. Look at the periodic table and deduce the number of valence electrons for aluminum and oxygen from the positions of the columns for those two elements. Draw a Lewis diagram representing the electron configuration of the hydrogen sulfide molecule, H 2S.

Ionic And Covalent Bonding Study Guide Answers

Chemistry - Chp 8 - Covalent Bonding - Study Guide. 1. Name Date Chapter 8 Study Guide Covalent Bonding. What is a covalent bond?.

What are the characteristics of molecular compounds (covalently bonded compounds) Characteristics of Ionic and Covalent Compounds Characteristics Ionic compound Covalent compound Representative element Formula unit Bond formation Transfer of one or more electrons between atoms Type of elements Metallic and nonmetallic Physical state Solid Melting point High (usually above 300 deg. Celcius) Solubility in water Usually high Electrical conductivity of Good conductor aqueous solution. Know how to write the Lewis electron dot structure for a molecular compound given its molecular formula. The trick part is figuring out how many bonds to draw.

It’s easy if you follow these steps.1. Count the number of 2. Subtract that number from 3. Divide your answer by 4. That number equals 5. Draw the structure with the correct number of bonds and don’t forget to make sureevery octet is full.

Example Questions(Use the steps above to figure out how many bonds there are in each molecule, then drawthe structures of each of the molecules.)1.) Br22.) CH43.) H204.) S25.) As2. Know how to draw resonance structuresExample Question(Draw all the possible resonance structures for the molecule below.)O3. What is a polar bond?. Know how to use Table S to determine the electronegativity difference and the chart below to determine what kind of bond will be made.

Electronegativity Differences and Bond Types Electronegativity Difference Range Most Probably type of bond 0.0-0.4 0.4-1.0 1.0-2.0 2.0Example Problems1.) What kind of bond will be produced between H and Cl?2.) What kind of bond will be produced between N and N?3.) What kind of bond will be produced between Li and Br?. What is a polar molecule?. Know how to denote the partial charges of a polar bond on a molecule with symbolsExample ProblemsFirst draw the structure of each molecule, then using symbols, write the partial chargescause by polar bonds on each molecule. 1.) HCl 2.) H20 3.) CF4 4.) CO2. What is a polar molecule?

(Explain why a molecule which has polar bonds can either be polar or non polar). Example problems1.) Is CO2 polar? (use a drawing of the molecule in your explanation)2.) Is H2C polar? (use a drawing of the molecule in your explanation). Rank the strengths of the intermolecular attraction forces1.2.3.4.This test will only be 12-15 questions, due to the shortened class time tomorrow. Thisreview sheet will have the basis of how to answer each question guaranteed.

Know thisreview sheet and you’ll do great on the test.Even though I don’t think you’ll need it, I will allow offer you the opportunity to usethis review sheet on tomorrows test. However if you choose to use it, the highest gradeyou may receive will be a 90%.