The Periodic Table

1. The Periodic Table How the periodic table is put together

3. What is the Periodic Table? • It is an organizational system for elements. Picture from www.chem4kids.com

4. Who created it? • The quest for a systematic arrangement of the elements started with the discovery of individual elements. •   By 1860 about 60 elements were known and a method was needed for organization.  • In 1869, Russian chemist Dimitri Mendeleev proposed arranging elements by atomic weights and properties. • The table contained gaps but Mendeleev predicted the discovery of new elements.

5. What do all the numbers mean ? From www.science-class.net

6. What do the symbols and numbers mean? • Symbol- one or two letter abbreviation which comes from the elements English or Latin name • Name- Elements common name • Atomic Number- Equal to the number of protons (+) or the number of electrons (-) in the electron cloud. • Atomic Mass- the mass of the atom or element. • (end)

7. So how is it arranged? • The genius of the periodic table “is that it is organized like a big grid. The elements are placed in specific places because of the way they look and act. If you have ever looked at a grid, you know that there are rows (left to right) and columns (up and down). The periodic table has rows and columns, too, and they each mean something different.” • quoted fromhttp://www.chem4kids.com/files/elem_pertable.html

8. You've got Your Periods... • Even though they skip some squares in between, all of the rows go left to right. When you look at a periodic table, each of the rows is considered to be a different period (Get it? Like PERIODic table.) • quoted fromhttp://www.chem4kids.com/files/elem_pertable.html

9. Periods = Rows • In the periodic table, elements have something in common if they are in the same row. • All of the elements in a period have the same number of atomic orbitals. • Every element in the top row (the first period) has one orbital for its electrons. All of the elements in the second row (the second period) have two orbitals for their electrons. It goes down the periodic table like that. • quoted fromhttp://www.chem4kids.com/files/elem_pertable.html

10. And you got your groups… • The periodic table has a special name for its columns, too. When a column goes from top to bottom, it's called a group. • quoted fromhttp://www.chem4kids.com/files/elem_pertable.html

11. Groups = Columns • The elements in a group have the same number of electrons in their outer orbital. • Every element in the first column (group one) has one electron in its outer shell. Every element on the second column (group two) has two electrons in the outer shell. As you keep counting the columns, you'll know how many electrons are in the outer shell. • There are some exceptions to the order when you look at the transition elements, but you get the general idea.

12. Outer Shell • The electrons in the outer shell (or outer orbital) are called Valence Electrons

13. How do we figure out the Valance Electrons? • The closest shell to the nucleus is called the "1 shell" (also called "K shell") • Followed by the "2 shell" (or "L shell") • Then the "3 shell" (or "M shell") • The shells correspond with the principal quantum numbers (n = 1, 2, 3, 4 ...) or are labeled alphabetically with letters used in the X-ray notation (K, L, M, …). Don’t need to know for quiz

14. Valance Electrons • Each shell can contain only a fixed number of electrons • The 1st shell can hold up to two electrons • The 2nd shell can hold up to eight (2 + 6) electrons • The 3rd shell can hold up to 18 (2 + 6 + 10) and so on. Do not need to know for quiz

15. Other than periods and groups, the table is divided into families. From www.science-class.net

16. ALKALI METALS • very reactive metals that do not occur freely in nature • malleable, ductile, good conductors of heat and electricity. • can explode if they are exposed to water From www.science-class.net

17. ALKALINE EARTH METALS • metals • very reactive • not found free in nature • Low Density • High Boiling Point • Found in compounds From www.science-class.net

18. TRANSITION METALS • ductile and malleable, and conduct electricity and heat • iron, cobalt, and nickel, are the only elements known to produce a magnetic field (paramagnetic). • Form compounds From www.science-class.net

19. RARE EARTH ELEMENTS • many are man-made • Not very rare, abundant • Green Element • Hard to isolate • Reactive, compounds and minerals From www.science-class.net

20. OTHER METALS • are ductile and malleable • are solid, have a high density • Good heat and electricity conductors • Reacts with H2O From www.science-class.net

21. METALLOIDS • have properties of both metals and non-metals • some of the metalloids are semi-conductors. This means that they can carry an electrical charge under special conditions. This property makes metalloids useful in computers and calculators From www.science-class.net

22. NON-METALS • not able to conduct electricity or heat very well (smi-conductors) • very brittle • Do not reflect light. • Reactivity depends on other atoms • Solid at room temperature • Used in computers, calculators, and phones. From www.science-class.net

23. HALOGENS • "halogen" means "salt-former" and compounds containing halogens are called "salts" • exist in all three states of matter • Reactive, bonds well with Group 1 From www.science-class.net

24. NOBLE GASES • do not form compounds easily • Happy/Inert Elements (Full outer shells) From www.science-class.net