1. Welcome to Chem 1A with Terri Bentzinger Chapter 2 E-mail: benzene4president@gmail Website: http://clas.sa.ucsb.edu/staff/terri/

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4. Atoms – Molecules - Ions – Ch. 2

5. 10 Ne 20.180 Atomic Number (Z) ⇒ # of protons Element Symbol Average atomic mass in amu or g/mol Mass Number (A) ⇒ sum of protons and neutrons **Note that mass number is NOT on the periodic table**

6. Atoms – Molecules - Ions – Ch. 2 2. Which of the following represents a pair of isotopes? a. 32 S and 32 S 2- b. O 2 and O 3 c. 15 7 N and 15 8 O d. 12 6 C and 13 6 C e. 18 8 O and 19 9 F

7. Atoms – Molecules - Ions – Ch. 2 Mass Number A Atomic Number Z

8. Atoms – Molecules - Ions – Ch. 2 3. Fill in the following table:

9. Atoms – Molecules - Ions – Ch. 2 4. What are ions? How are ions generated?

10. Atoms – Molecules - Ions – Ch. 2 5. Metals tend to gain or lose electrons? What charge do group 1 metals form? What charge do group 2 metals form? What charge do group 3 metals form?

11. Atoms – Molecules - Ions – Ch. 2 Non-metals Metalloids Metals

12. Atoms – Molecules - Ions – Ch. 2 6. Non-metals tend to gain or lose electrons? What charge do group 8 non-metals form? What charge do group 7 non-metals form? What charge do group 6 non-metals form? What charge do group 5 non-metals form?

13. Atoms – Molecules – Ions – Ch. 2 7. How could you distinguish between ionic compounds, molecular compounds and acids?

14. Atoms – Molecules – Ions – Ch. 2 CompoundType of CompoundName LiHCO 3 Na 2 SO 3 (NH 4 ) 3 PO 4 Fe(OH) 3 SnS 2 HF (g) HClO (aq) H 2 C 2 O 4(aq) SBr 6 CO P2O5P2O5 8.

15. Atoms – Molecules – Ions – Ch. 2 Naming Ionic Compounds First Name (cation) Second Name (anion) Naming Ionic Compounds First Name (cation) Second Name (anion) 1. metals with fixed charges (Grps 1,2,3,Ag, Zn and Cd) ⇒ use the elements name as is 2. metals with varying charges (all other metals) ⇒ use the elements name and a Roman numeral 3. NH 4 + ⇒ ammonium 1. metals with fixed charges (Grps 1,2,3,Ag, Zn and Cd) ⇒ use the elements name as is 2. metals with varying charges (all other metals) ⇒ use the elements name and a Roman numeral 3. NH 4 + ⇒ ammonium 1. monoatomic ⇒ elements name with the suffix –ide 2. polyatomic ⇒ you’ll eventually memorize these names 1. monoatomic ⇒ elements name with the suffix –ide 2. polyatomic ⇒ you’ll eventually memorize these names

16. Atoms – Molecules – Ions – Ch. 2 Common Polyatomic Ions

17. Atoms – Molecules – Ions – Ch. 2 Naming Acids Acids without oxygen Acids with oxygen fox Naming Acids Acids without oxygen Acids with oxygen fox 1. Add prefix hydro to the anion’s name 2. Change suffix to ic acid ex: HCN ⇒ hydrocyanic acid or HF ⇒ hydrofluoric acid 1. Add prefix hydro to the anion’s name 2. Change suffix to ic acid ex: HCN ⇒ hydrocyanic acid or HF ⇒ hydrofluoric acid Change suffix of anion in the acid ate ⇒ ic acid ite ⇒ ous acid ex: HNO 2 ⇒ nitrous acid vs. HNO 3 ⇒ nitric acid Change suffix of anion in the acid ate ⇒ ic acid ite ⇒ ous acid ex: HNO 2 ⇒ nitrous acid vs. HNO 3 ⇒ nitric acid

18. Atoms – Molecules – Ions – Ch. 2 Naming Covalent/Molecular Compounds 1. Add a Greek prefix to the first element’s name if there’s 2 or more 2. Always add a Greek prefix to the 2 nd element and change the suffix to –ide ex: NF 3 ⇒ nitrogen trifluoride Naming Covalent/Molecular Compounds 1. Add a Greek prefix to the first element’s name if there’s 2 or more 2. Always add a Greek prefix to the 2 nd element and change the suffix to –ide ex: NF 3 ⇒ nitrogen trifluoride

19. Atoms – Molecules – Ions – Ch. 2 NameCompound TypeFormula calcium cyanide aluminum sulfate lead(IV) oxalate hydrosulfuric acid sulfuric acid phosphorous acid sulfur trioxide carbon tetrachloride 9. Write the chemical formulas for the following compounds:

20. Atoms – Molecules – Ions – Ch. 2 10. Here are some common names that you’re expected to know; write the chemical formula. a. water b. methane c. ammonia

21. Atoms – Molecules – Ions – Ch. 2 11. An element’s most stable ion forms an ionic compound with chlorine having the formula XCl 2. If the mass number of the ion is 25 and it has 10 electrons… a. Name the compound b. How many neutrons does X have?

22. Atoms – Molecules – Ions – Ch. 2 You have completed ch. 2

23. Ch 2 - Answer Key

24. 2. Which of the following represents a pair of isotopes? d. 12 6 C and 13 6 C Isotopes are atoms of the same element so they have the same number of protons however they differ by the number of neutrons or mass number 3. IsotopeProtonsNeutronsElectronsCharge 47 Ti222522none 90 Sr 2+ 3852362+ 32 P 3– 1517183–

25. Ch 2 - Answer Key 4. What are ions? How are ions generated? Ions are charged atoms (monoatomic) or charged groups of atoms (polyatomic) – ions are generated due the gain or loss of electrons producing anions (negative) and cations (positive) 5. Metals tend to gain or lose electrons? What charge do group 1 metals form? 1+ (Alkali metals) What charge do group 2 metals form? 2+ (Alkaline earth metals) What charge do group 3 metals form? 3+ (Boron group)

26. Ch 2 - Answer Key 6. Non-metals tend to gain or lose electrons? What charge do group 5 non-metals form? 3– (nitrogen family) What charge do group 6 non-metals form? 2– (oxygen family) What charge do group 7 non-metals form? 1– (halogens) What charge do group 8 non-metals form? No ions (noble gases)

27. Ch 2 - Answer Key 7. How could you distinguish between ionic compounds, covalent compounds and acids? Ionic compounds => cation (typically metal or NH 4 ) and anion (typically nonmetal) Covalent compounds => only nonmetals Acids => aqueous covalent compounds that begin with hydrogen

28. Ch 2 - Answer Key 8.

29. Ch 2 - Answer Key 9.

30. Ch 2 - Answer Key 10. Here are some common names that you’re expected to know; write the chemical formula. a. Water – H 2 O b. Methane – CH 4 c. Ammonia – NH 3

31. Ch 2 - Answer Key 11. An element’s most stable ion forms an ionic compound with chlorine having the formula XCl 2. If the mass number of the ion is 25 and it has 10 electrons… a. Name the compound magnesium chloride b. How many neutrons does X have? 13