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The Periodic Table. Chapter 5. Alchemy & Diderot's Alchemical Chart of Affinities (1778) : . Dalton's elements and symbols (1808): . The Bayley Pyramid Periodic Table. Mohammed Abubakr's circular periodic table is one alternative to the standard periodic table of the elements. .
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The Periodic Table Chapter 5
Mohammed Abubakr's circular periodic table is one alternative to the standard periodic table of the elements.
AtomFlowers A periodic table that gives a representation of the electron orbitals that look like flowers
1750 = 17 elements known Mostly common metals After 1750, more chemists begin to study elements many more elements discovered faster Needed a way to organize elements 1789 Antoine Lavoisier grouped elements based on type Metals, nonmetals, gases & earths 1860 Mendeleev What was going on in history during this time? Why is this organization limited? Organizing the Elements
Organized elements like a deck of cards 1st order by mass 2nd property patterns esp. rxns with O & H Draw an example of ordering strategy Mendeleev’s Periodic Table
5 6 7 A 2 4 8 9 10 J Q K
3 A 2 4 5 6 7 8 9 10 J Q K
Organized elements like a deck of cards 1st order by mass 2nd property patterns esp. rxns with O & H Rows (called periods) Mass increases from left to right Columns (called groups) Mass increases from top to bottom Similar properties Draw an example of ordering strategy Draw a small periodic table to illustrate rows and columns groups periods Mendeleev’s Periodic Table
groups periods
Mendeleev’s Periodic Table • Left blanks for elements not discovered yet • Why remember Mendeleev if he wasn’t the first to come up with a P.T.? • Best organization strategy • Used to make accurate predictions about what elements were yet to be discovered
Mendeleev’s Periodic Table • EX: Gallium • Predicted similar properties to aluminum • Soft metal • Low melting point • Density ~ 5.9 g/cm3 • Truth about gallium: • Soft metal • Melting pt 29.7˚C • Density 5.91 g/cm3 • Further proof his PT was good: • Discovery of scandium and germanium Would gallium be a solid, liquid or gas at room temperature (20-22˚C)?
Check your understanding • Pg 126 reading strategy • Pg 127 figure 3 • Pg 129 figure 4 (already done ) • Pg 129 assessment, #1-8
REMINDER!!! • Open note reading quiz WARNING
5.2 • More on Mendeleev (note: 1860) • Did not know about protons • Did not know that all atoms in an element have the same # of protons • His PT arranged by mass, ours by atomic #
5.2 • Periods • Rows (side-to-side) • # of periods = # of electron energy levels • Groups • Columns (up-and-down) • Similar properties • Similar electron configuration • Determines chemical properties
5.2 • Atomic mass • # given on PT is an average of the element’s isotope masses • Weighted avg.s • Atomic mass = avg. mass of isotopes compared to how common they are • AMU • Atomic Mass Unit • Unit of mass for atoms (like grams but much smaller!)
5.2 • Classes of Elements • Solid, liquid, gas dependant on temp. • Occur naturally vs. those that do not (man-made) • Metals, nonmetals, metalloids
5.2 • Metals • Most elements are metals (+75%!) • Physical properties • Good conductors • Solids at room temp. (except for Hg) • Malleable • ductile • Chemical properties • Some are reactive, others are not (to rust or not to rust?)
5.2 • Special Metals • Transition metals • Chemical properties • Form compounds with distinctive colors • Lanthanide & actinide series
5.2 • Nonmetals • Physical properties • Poor conductors • Brittle • Most are gasses at room temp. (low bp) • Chemical properties • Vary some very reactive, others not at all • Most reactive = group 17 • Least reactive = group 18
5.2 • Metalloids • Physical properties • Conductivity varies with temp. • Semi-conductors computer chips “Silicon Valley”
Chapter 5 section 3pg 139-149 Part I: pg 139 & ions Part II: pg 140-145 Part III: pg 146-149
5.3 Part I • Valence electrons • Electrons in the outermost energy level • Chemical properties depend on the number of valence electrons • What does this mean after learning about the organization of the PT? Groups have similar properties so they must also have similar #s of valence electrons
5.3 Part I • Octet • magic # in chemistry = • Valence orbitals can hold no more than 8 e- • All atoms want a full valence (8 e-) or none (all or nothing) • Exceptions: H & He Why?
5.3 Part I • Ions • Atoms that gain or loose e- to fill or empty the valence orbital 1p+ +1
5.3 Part I • Ions • Atoms that gain or loose e- to fill or empty the valence orbital 2p+ Ø
5.3 Part I • Ions • Atoms that gain or loose e- to fill or empty the valence orbital 3p+ +1
5.3 Part I • Ions • Atoms that gain or loose e- to fill or empty the valence orbital 4p+ +2
5.3 Part I • Ions • Atoms that gain or loose e- to fill or empty the valence orbital 5p+ +3
5.3 Part I • Ions • Atoms that gain or loose e- to fill or empty the valence orbital 6p+ +4 `
5.3 Part I • Ions • Atoms that gain or loose e- to fill or empty the valence orbital 6p+ -4 `
5.3 Part I • Ions • Atoms that gain or loose e- to fill or empty the valence orbital 7p+ -3 `
5.3 Part I • Ions • Atoms that gain or loose e- to fill or empty the valence orbital 8p+ -2 `
5.3 Part I • Ions • Atoms that gain or loose e- to fill or empty the valence orbital 9p+ -1 `
5.3 Part I • Ions • Atoms that gain or loose e- to fill or empty the valence orbital 10p+ Ø `
5.3 Part I • Ions • Atoms that gain or loose e- to fill or empty the valence orbital 11p+ +1 `