Practice Quiz

1. Practice Quiz Ionic and Covalent Bonding

2. Remember….these are our targets (so far)… • Describe how one can identify a compound as ionic or molecular. • Explain the role and location of electrons in a covalent bond. • Describe the change in energy and stability that takes place when a covalent bond forms. • Explain the difference in single, double and triple covalent bonds. • Distinguish between polar and non-polar covalent bonds based on electronegativity differences. • Contrast ionic and molecular substances in terms of their physical characteristics and the types of forces that govern their behavior. • Show the process of how an ionic bond forms. • Explain how properties of ionic compounds depend on the nature of ionic bonds. • Describe the formation of a salt. • Draw Lewis Dot diagrams (electron dot diagrams) of elements. • Rationalize the properties of a substance based on its type of bonding.

3. Has how many valence electrons? 2 4 10 12 14 The element represented by [Ar] 4s2 3d10 4p2 Is which element? Titanium Silicon Germanium Selenium

4. The element represented by [He] 2s2 2p4 Would need to share how many electrons with another atom to achieve a noble gas configuration? • 2 • 4 • 6 • 8 • None of these are correct.

5. Use the electron dot diagrams to answer the following question Which combination of elements would likely form a covalent bond? • V and X • V and Z • W and Y • W and Z • Y and Z

6. If two atoms (X and Z) were to covalently bond to each other, what molecule would result? • XZ • X2Z3 • X3Z • XZ3 • It is impossible to answer because atoms of X will not covalently bond .

7. If two atoms of Y could covalently bond together, what type of bond would result? a single, polar bond a double, nonpolar bond a triple, polar bond a single, nonpolar bond It is impossible to answer because two atoms of Y will not covalently bond.

8. Which of the following compounds could be created by ionic bonding? • VZ • WY • XZ3 • YZ2 • None of These

9. Of the electron dots structures below, which would represent an atom of Sulfur? • V • W • X • Y • Z Which of the electron dots would represent a metal atom? V W X Y Z

10. Covalent bonding normally occurs between which types of elements? metals only non-metals only metals and non-metals More than one of these are correct. None of these are correct.

11. Of the three major types of bonding (ionic, covalent, metallic) which ones are based on electrostatic attractions between opposite charges? A)only ionic bonding B)only ionic and covalent bonding C)only ionic and metallic bonding D)ionic, covalent and metallic bonding E)none of the above

12. Ionic compounds normally conduct electricity A)when in the solid state. B)only when molten. C)when in aqueous solution or molten. D)only when in aqueous solution. E)when a solid or in aqueous solution.

13. Order the following by decreasing bond length: C≡C, C=C, C-C A) they are all the same B) C≡C, C=C, C-C C) C≡C, C-C, C=C D) C-C, C=C, C≡C E) C=C, C-C, C≡C

14. If a process in salt formation is exothermic, when we write an equation, where would “energy” appear? • On the left side of the arrow • On the right side of the arrow • On top of the arrow • On the reactants side • On the products side

15. Which selection below is an endothermic reaction that occurs in the formation of a salt? • Na + energy  Na+ + e- • Na + e- Na+ + energy • Cl + energy Cl- + energy • Cl + e-Cl- + energy

16. Which of the following is NOT a process in the formation of a salt? • Na + energy  Na+ + e- • Na(s) + energy  Na(g) • Na+ + Cl-NaCl + energy • Cl + energy Cl- + e-

17. Electronegativity is a measure of A) the energy needed to remove an electron from an atom. B) the energy released when an electron is added to an atom. C) the magnitude of the negative charge on an electron. D) the attraction by an atom for electrons in a chemical bond. E) the magnitude of the negative charge on a molecule.

18. Which of the following elements is the most electronegative? A) C B) Si C) As D)Cl E)Sr

19. Consider an isolated H-C bond in an organic compound. Based on the electronegativities of the two elements, which of the following best describes the net charge on the carbon atom? A) no polarization of the bond, i.e. no net charge B) a full negative charge C) a full positive charge D) a partial negative charge E) a partial positive charge

20. Which one of the following properties is not characteristic of typical metals? A) moderately high melting point B) high boiling point C) brittleness D) good electrical conductor when solid E) good electrical conductor when molten

21. When an atom loses an electron, it A. becomes a negative ion B. becomes a positive ion C. forms a covalent bond D. gains protons E. becomes a neutral atom

22. Which of these is a property of an ionic compound? A. Low melting point B. Poor conductor of electricity C. Crystal shape D. Shared electrons E. Forms a molecule

23. Ionic compounds have A. a positive charge B. a negative charge C. no electrical charge D. a changing electrical charge E. a variable electrical charge depending on the ions involved

24. What kind of bond is each picture showing? Covalent Bonds! Answer… Which of the above diagrams is showing a molecule made of double bonds? Answer… Which is showing a molecule made of POLAR bonds? Answer…

25. The diagram below is showing what? Answer… The energy changes that occur as a covalent bond forms. Which part of the diagram is showing when a molecule is most stable? AA BB C D Answer… BB This is when the bond is at its lowest energy!!!

26. The octet rule helps predict the number of electrons an atom will gain or lose False True or

27. Ionic substances are usually soft and have a low melting point. False True or So what are some characteristics of ionic substances?

28. Are you a bonding ?