1. The Periodic Table Glenn V. Lo Department of Physical Sciences Nicholls State University

2. Periodic Table Tabulates elements in a manner that facilitates understanding of trends and similarities in properties A (horizontal) row of elements in the periodic table is called a PERIOD. A (vertical) column of elements in the periodic table is called a GROUP or FAMILY

3. Example Which of the following belongs to period 3? A. Na, B. Sc, In

4. Classifying elements Main or representative: Columns 1, 2, and 13 through 18. Traditionally, these are numbered IA, IIA, IIIA, etc. Transition: Columns 3 through 12. Traditionally, these are the numbered IIIB, IVB, VB, etc. Inner transition elements: lanthanides and actinides (two bottom rows). Lanthanides are part of period 6; actinides are part of period 7.

5. Group names to know

6. Metals, nonmetals, metalloids Metallic elements: found on left side of periodic table Metal characteristics: Shiny Malleable Ductile Good electrical conductor Good heat conductor Metalloids: B, Si, Ge, As, Sb, Te, Po

7. Example Which element is a good electrical conductor? A. Cu, B. Ge, C. Kr

8. Post transition metals All transition elements are also referred to as transition metals Post-transition metals: representative elements between the transition metals and metalloids. Ga, In, Sn Tl, Pb, Bi

9. Physical States of Elements Under ordinary conditions:

10. Typical monatomic cations Metals tend to become cations. Alkali metals (IA) always +1. Alkaline earth metals: +2 always Al: +3 always Transition and post-transition metals: varies (+1 to +4),  Most common charge: +2  Zn, Cd, and Hg: always +2

11. Typical monatomic cations Write down the symbols of the ions formed from the following atoms: sodium, potassium, calcium, barium, aluminum, zinc

12. Names of cations Names of naturally-occurring monatomic cations Main group cations: same as name of element. Example: Na + is sodium ion, Ca 2+ is calcium ion Transition and post-transition cations: same as name of element, but specify charge in Roman numerals in parentheses. Example: Co 3+ is cobalt(III).

13. Example Which of the following is magnesium ion? A. Mg +, B. Mg -, C. Mg 2+, D. Mg 3+

14. Example What is the formula of lead(IV) ion?

15. Typical monatomic anions Nonmetals in groups VA, VIA and VIIA tend to become anions with charges of –1, -2, and –3, respectively; name endings change to ide. Example: Fluorine (F) becomes fluoride (F - ) Oxygen (O) becomes… Nitrogen (N) becomes…

16. Typical anions Write down the symbols for the following ions: bromide, nitride, sulfide, chloride, iodide

17. Typical Monatomic Ions: summary

18. Chemical bonding Nonmetals and metalloids tend to share electrons with other nonmetal atoms. Atoms sharing electrons are said to be in a covalent bond. Covalent bonding is what keeps atoms together in molecules and polyatomic ions. Nonmetal atoms tend to gain electrons from metal atoms forming cations and anions. Oppositely charged ions are attracted to each other; the attraction is called an ionic bond.

19. Chemical bonding Metals may form covalent bonds with other atoms. Common examples: Polyatomic ions such as mercury(I), chromate, dichromate, and permanganate: Hg 2 2+, CrO 4 2-, Cr 2 O 7 2-, MnO 4 - Complex ions such as Cu(H 2 O) 4 2+ Coordination compounds In metallic solids, the electrons are loosely held among the metal atoms. The bonding among the large number of metal atoms is called metallic bonding.

20. Molecular elements These elements are typically found as a collection of molecules under ordinary conditions Halogens: diatomic molecules (F 2, Cl 2, Br 2, I 2 ) Other diatomics: O 2, N 2, H 2 Polyatomic: P 4, S 8 Diamond can be considered as one giant molecule consisting of covalently bonded C atoms Graphite (such as the “lead” in your pencil) can be considered as sheets of flat giant molecules consisting of covalently bonded C atoms. The flat giant molecules are called graphene. The molecules in the “ozone” layer that protects us from harmful rays from the sun: O 3

21. Inert atoms Noble gas (VIIIA) atoms tend not to form ions or molecules under ordinary conditions. Which of the following elements are you most likely to find in nature as a collection of neutral atoms (a “monatomic gas”)? A. Na, B. Ne, C. F

22. Test Yourself Which of the following elements is a metal that belongs to a main group or representative group? A. Magnesium, B. zinc, C. sulfur, D. uranium

23. Test Yourself Which of the following elements is a transition metal? A. silicon B. lead C. sodium D. chromium

24. Test Yourself All of the following are true, except... A. Sodium is an alkali metal, B. Neon is a noble gas, C. Calcium is an alkaline earth metal, D. Oxygen is a halogen

25. Test Yourself Which of the following elements is the best electrical conductor? A. Carbon, B. germanium, C. manganese, D. iodine

26. Test Yourself Which of the following is a metalloid? A. potassium B. silicon C. iron D. helium

27. Test Yourself Which of the following elements is a post-transition metal? A. Silicon, B. lead, C. sodium, D. chromium

28. Test Yourself Which of these elements is not a gas under ordinary conditions? A. bromine B. helium C. hydrogen D. oxygen

29. Test Yourself Which of the following naturally-occurring ions is paired with its correct symbol? A. potassium ion, K 2+, B. sulfide, S 3-, C. barium ion, Ba 2+, D. iodide, I +

30. Test Yourself Which of the following pairs of atoms is most likely to form an ionic bond? A. C and H, B. Ca and H, C. Hg and Hg

31. Test Yourself What type of bond is more likely between a carbon atom and an oxygen atom? A. ionic B. covalent C. metallic

32. Test Yourself What type of bond holds the atoms together in the polyatomic ions chromate (CrO 4 2- ) and nitrate (NO 3 - )? A. ionic, ionic B. ionic, covalent C. covalent, ionic D. covalent, covalent

33. Test Yourself Which of these elements naturally occurs as a diatomic gas under ordinary conditions? A. bromine B. iodine C. mercury D. chlorine

34. Test Yourself Which of these naturally occurs as a monatomic gas under ordinary conditions? A. helium B. sodium C. oxygen D. nitrogen