The Periodic Table

1. The Periodic Table Chapter 6

2. History of the Periodic Table • In 1869, a Russian chemist and teacher, Dmitri Mendeleev, published the first table of the elements. • He arranged them in order of increasing atomic mass.

3. Modern Periodic Table • In the modern periodic table, elements are arranged in order by increasing atomic number.

4. Periods • Each horizontal row on the table is called a period. • The number of the period tells you how many electron shells that atom has around its nucleus.

5. Groups • Vertical columns are called groups, and elements within a group share similar properties.

6. 1A: Alkali Metals • The first group, 1A, is the alkali metals. These include Li, Na, K, Rb, Cs, and Fr. Color them orange. • These are soft, silvery colored metals. • They all have 1 valence electron, and are very reactive.

7. 2A: Alkaline Earth Metals • The second group, 2A, are the alkaline earth metals. These include Be, Mg, Ca, Sr, Ba, and Ra. Color them blue. • They are shiny, silvery white metals. • They have 2 valence electrons, and are slightly less reactive than group 1A.

8. Transition Metals • The transition metals include the center of the table, from Sc to Zn down to Uub and over to Lr. Color them dark blue. • They are ductile: can be drawn into wires, • Malleable: can be pounded into thin sheets, • Conductive: heat and electricity flow through them

9. 7A: Halogens • The halogens in group 7A include F, Cl, Br, I, and At. Color them yellow. • They are the most reactive non-metals. They are gases and require only one electron to fill their valence shells.

10. 8A: Noble gases • Group 8A are the noble gases and include He, Ne, Ar, Kr, Xe, and Rn. • Color them red. • These are inert, or un-reactive gases. They have full valence electron shells.

11. Metalloids • Metalloids include B, Si, Ge, As, Sb, Te, and At. • Color them purple. • They have properties of both metals and non-metals.

12. Non-metals • Non-metals are poor conductors of heat and electric current. They include C, N, O, P, S, and Se. • Color them green. • They can be solid or gas.

13. Poor Metals • Al, Ga, In, Sn, Tl, Pb, Bi, Po, and Uuq are all poor metals. • Color them grey. • They are metals, but do not conduct electricity well.

14. Lathanide Series • The lathanide elements can all be found naturally on Earth. They are called Rare-Earth metals. • Color them brown.

15. Actinide Series • The actinide elements are mostly made in laboratories, and are all radioactive. They are rare Earth metals too. • Color them brown as well.

16. Periodic Table Practice • Using your notes, please complete the problems on the practice sheet. • If you finish, turn them in, otherwise they become homework.

17. Periodic Trends • As you move down or across the table, trends or patterns become evident in physical and chemical properites.

18. Atomic Size • As you go down a group atoms increase in size. • As you go across a period to the right, atomic size decreases. • So Fr is the biggest atom, and F is the smallest.

19. Ionization Energy • The energy required to remove an electron from an atom is called ionization energy. • The harder it is to remove an electron, the higher the ionization energy is.

20. Ionization Energy • The bigger an atom is, the easier it is to remove an electron because they are farther from the nucleus and held less tightly. • Therefore, larger atoms have lower ionization energy, and smaller atoms have higher ionization energy.

21. Ionization Energy • Ionization energy increases as you go up a group. • Ionization energy increases as you go across a period to the right. • So the biggest atom, Fr, has the lowest ionization energy, and the smallest, F, has the highest.

22. Electronegativity • Electronegativity is the ability of an atom of an element to attract electrons when the atom is in a compound. • Smaller atoms are able to attract electrons more easily, and have higher electronegativity values.

23. Electronegativity • Electronegativity increases as you go up a group or across a period to the right. • The smallest atom, F, has the highest electronegativity. • The largest atom, Fr, has the lowest electronegativity.

24. What is the effect of atomic structure on the growth of crystals? • Follow your lab report guidelines to record this experiment in your notebooks. • Setup and results: