1. The Periodic Table Chapter 5 Pg. 126-147

2. Organizing the Elements Chapter 5 Section 1 Pg. 126-129

3. The Search for Order Until 1750, only 17 elements had been identified- mainly _____ As the number of known elements grew, so did the need to _____ them into groups based on their ________. 1789, French chemist _______- grouped the known elements into categories: metals, nonmetals, gases, and earths

4. 1860 (Russian chemist and teacher) ________ was looking for the best way to organize the information of __ known elements Found a way to approach the problem while playing a version of ______ (card game)

5. Made a “_________” of the elements: each card had the element’s name, mass, and properties Also paid attention to how each element behaved in ________ with oxygen and hydrogen When he lined up the cards in order of _______ mass, a pattern emerged

6. Mendeleev’s Proposal – Mendeleev arranged the elements into ____ in order of increasing mass so that elements with _____ properties were in the same column. – _____ arrangement: columns were organized by properties instead of suits – Within column: the masses ______ from top to bottom – ___________- an arrangement of elements in columns, based on a set of properties that repeat from row to row

7. Could not make a complete table of the elements because many elements had not yet been ________. Mendeleev left _____ in his table for the missing elements, he was confident that the gaps in his table would be filled by new elements He used ________ of elements located near the blank spaces in his table to _____ properties for undiscovered elements

9. Mendeleev was ___ the first to arrange elements in a periodic table or leave spaces in the table for missing elements Mendeleev was the f____ to offer the best explanation for how the properties of an element were related to its ______ in the table The placement of elements on the table reveals the link between the atomic ________ of elements and their properties

10. Mendeleev _____ missing elements – Ex: eka-aluminum (belonged one space below aluminum on the table) He predicted that eka- aluminum would be a soft metal with a low melting point and a density of 5.9 g/cm 3

11. 1875- French chemist discovered a new element- named it _______ (Ga) in honor of ______ – Gallium is a soft metal with a melting point of 29.7°C and a density of 5.91 g/cm 3 The close _____ between Mendeleev’s predictions and the actual properties of new elements showed how ______ his periodic table could be

12. Chapter 5 Section 2 Pg. 130-138

13. The Modern Periodic Table Piano keys are in ______ (the interval between any two notes with the same name) – octa- means eight Because the scale _______ at regular eight- note intervals, the scale is an example of a periodic pattern The sounds of musical notes that are separated by an octave are related, but they are not ________- similar to elements in columns

14. Mendeleev developed his periodic table ______ the discovery of ______ In the modern periodic table, elements are arranged by _______ atomic number (number of protons)

15. Periods – Each row is a _______ – The number of elements per period varies because the number of available _____ increases from energy level to energy level

16. The Periodic Law

17. Groups – Each ______ is a group – The elements within a group have ______ properties – Properties of elements repeat in a __________ way when atomic numbers are used to arrange elements into groups – Members of a group have similar chemical properties – Periodic ____- the pattern of repeating properties

18. The Periodic Law

19. Atomic mass is a value that depends on the distribution of an element’s ______ in nature and the masses of those isotopes

20. Atomic Mass Units – The mass of an atom in grams is extremely ____ and not very useful because the samples of matter that scientists work with contain ______ of atoms – To have a convenient way to compare the masses of atoms, scientists chose one isotope to serve as a _______ – An atomic mass unit (amu) is defined as one twelfth the mass of a carbon-12 atom

21. Isotopes of Chlorine – Most elements exist as a _____ of two or more isotopes – There are two ______ isotopes of chlorine, chlorine-35 and chlorine-37 – An atom of chlorine-35 has 17 protons and 18 neutrons – An atom of chlorine-37 has 17 protons and 20 neutrons

22. Weighted Averages – The isotope that occurs in _____ about 75% of the time (chlorine-35) contributes three times as much to the ______ as the isotope that occurs in nature about 25% of the time (chlorine-37)

23. First- elements are classified as solids, liquids, or gases, based on their _____ at room temperature Black: solids Purple: liquids Red: gases Second- elements are divided into those that occur ________ and those that do not – All but 2 elements (1-92) occur on ____ – Elements 93 and higher do not occur naturally (white)

25. Third- classification system puts elements into _______ based on their general _______; elements are classified as metals, nonmetals, and metalloids – Metals: on left – Nonmetals: on right – Metalloids: in between

27. Metals – _______ of the elements (blue boxes) – Good conductors of electric current and heat – ______ at room temperature (except mercury) – Most are malleable – Many are ________ (can be drawn into thin wires) – Some are extremely reactive and some do not react easily

28. Metals continued… – __________ metals: metals in groups 3 through 12; form a _______ between the elements on the left and right sides of the table one property of many transition metals is their ability to form compounds with distinctive colors

30. Nonmetals – Elements that are _____ conductors of heat and electric current – Low boiling points – Many are ______ at room temperature – Those that are solid at room temperature tend to be ______ – _______ is the most reactive nonmetal

31. Metalloids – Elements with properties that fall ________ those of metals and nonmetals – Ability to conduct electric current varies with __________ Si and Ge good insulators at low temperatures and good conductors at high temperatures

33. _______ a period from left to right, the elements become less metallic and more nonmetallic in their properties Most _____ metals are on left side of table Most reactive nonmetals are on right side in Group __

34. Representative Groups Chapter 5 Section 3 Pg. 139-149

35. Why is Hydrogen on the left side of the periodic table with the active metals? – It is a nonmetal ___ that seems to have more in common with the nonmetals in Group 17 Hydrogen’s location is related to its ________ configuration, not its properties

36. _______ electron is an electron that is in the highest occupied energy level of an atom – they play a key role in chemical reactions Properties vary across a period because the number of valence electrons ______ from left to right Elements in a group have similar properties because they have the _____ number of valence electrons

38. Group 1 – Have ______ valence electron and are extremely reactive – Found in nature only in compounds because they are so ______ The reactivity of alkali metals _________ from the top of Group 1 to the bottom Sodium and potassium are stored under oil to keep them from reacting with the ______ and water vapor in air

40. Group 2 – All have ___ valence electrons – Harder metals than metals in group 1 Differences in reactivity among the alkaline earth metals are shown by the ways they react with _____

42. ______________ – Plays a key role in the process that uses sunlight to produce sugar in plants – The center of _______ is magnesium – A mixture of magnesium and other metals can be as strong as steel, but much lighter

43. Calcium – Body needs calcium to keep bones and teeth ______ – Calcium _______: compound of calcium, carbon, and oxygen- main ingredient in chalk, limestone, coral, and pearls

44. Group 3 – All have ___ valence electrons __________ is the most abundant metal in Earth’s crust

45. Group 4 – 1 nonmetal (carbon), 2 metalloids (silicon, germanium) and 2 metals (tin, lead) – Each has ____ valence electrons Except for water, most of the compounds in your body contain _______ Silicon is the ______ most abundant element in Earth’s crust

47. Group 5 – Has 2 nonmetals (N, P), 2 metalloids (As, Sb), and 1 metal (Bi) – Wide range of _______ properties – All have ___ valence electrons – Nitrogen: nonmetal gas – Phosphorus: solid nonmetal – Bismuth: a dense metal Besides nitrogen, fertilizers often contain ________

49. Group 6 – All have ___ valence electrons _______ is the most abundant element in Earth’s crust – Complex forms of life need oxygen to stay alive because it releases the ______ stored in food – Ozone is another form of oxygen; at ground level it is an irritant, at upper levels it absorbs harmful radiation emitted by the sun _______ was one of the first elements to be discovered- found in large natural deposits

51. Group 7 – Each has ___ valence electrons Despite their physical differences, the halogens have similar _______ properties – Highly reactive _______ (fluorine most reactive, chlorine is a close second) – React easily with most metals

52. Group 8 – Each has ___ valence electrons with the exception of Helium which has 2 – Colorless and _____ and extremely __________ Some light bulbs are filled with _____ because the glowing filament in the bulbs will not react with argon as it would react with oxygen