1 DMITRI MENDELEEV ORGANIZED KNOWN ELEMENTS INTO A TABLE POSITIONED ELEMENTS SO ELEMENTS WITH SIMILAR PROPERTIES IN COLUMNS RECOGNIZED THAT PROPERTIES REPEATED PERIODICALLY IN A PATTERN

2 MENDELEEV’S PT

3 MENDELEEV’S PREDICTIONS PREDICTED PROPERTIES OF YET UNDISCOVERED ELEMENTS PREDICTIONS BASED ON TRENDS IN COLUMNS AND ROWS PREDICTIONS WERE VERY ACCURATE

4 PREDICTED PROPERTIES

5 MODERN PREDICTIONS

6 MODERN PERIODIC TABLE MODERN PERIODIC TABLE IS ARRANGED BASED ON ATOMIC NUMBER

7 LONG FORM PT

8 TYPES OF ELEMENTS

9 GROUP NAMES

10 METAL LOSES ELECTRONS WHEN REACTING TYPICALLY HAS 1-3 VALENCE ELECTRONS FOUND LEFT OF THE STAIR STEPS ON THE PERIODIC TABLE

11 NONMETAL GAINS ELECTRONS WHEN REACTING TYPICALLY HAS 5-7 VALENCE ELECTRONS FOUND RIGHT OF THE STAIR STEPS ON THE PERIODIC TABLE

12 METALLOID CAN GAIN OR LOSE ELECTRONS WHEN REACTING A SUBSTANCE HAVING 3-5 VALENCE ELECTRONS FOUND ALONG THE STAIR STEPS ON THE PERIODIC TABLE

13 NOBLE GASES DO NOT GAIN OR LOSE ELECTRONS – SO THEY DO NOT REACT HAVE FULL VALENCE SHELL (2 FOR He AND 8 FOR OTHERS) FOUND IN RIGHTMOST COLUMN OF PERIODIC TABLE

14 FAMILY CHARACTERISTICS ALL HAVE THE SAME NUMBER OF VALENCE ELECTRONS SIMILAR CHEMICAL PROPERTIES TRENDS OF DENSITY, MP, BP TREND OF INCREASING OR DECREASING REACTIVITY

15 PERIODIC LAW PROPERTIES OF ELEMENTS TEND TO REPEAT IN A PATTERN WHEN THE ELEMENTS ARE ARRANGED IN ORDER OF INCREASING ATOMIC NUMBER

16 ATOMIC SIZE PATTERNS GET SMALLER GOING FROM LEFT TO RIGHT ACROSS A PERIOD –ADDING PROTONS PULLS ENERGY LEVELS CLOSER –ELECTRONS ADDED TO VALENCE SHELL GET LARGER GOING FROM TOP TO BOTTOM IN A GROUP –NEED MORE ENERGY LEVELS TO FIT ALL ELECTRONS

17 ION SIZES CATIONS ARE SMALLER THAN NEUTRAL ATOMS –LOST VALENCE SHELL, SO FEWER ENERGY LEVELS ANIONS ARE LARGER THAN NEUTRAL ATOMS –ADDED ELECTRONS REPELL TO MAKE VALENCE SHELL LARGER

18 UNITS FOR ATOM SIZE ANGSTROMS ( Å ) = 1 x m PICOMETERS (pm) = 1 x m

19 ATOMS AND CATIONS

20 ATOMS AND ANIONS

21 ATOMIC SIZE (in pm)

22 IONIZATION ENERGY ENERGY INPUT NEEDED TO REMOVE THE OUTERMOST VALENCE ELECTRON FROM AN ATOM INCREASES FROM LEFT TO RIGHT DECREASES FROM TOP TO BOTTOM

23 ELECTRON AFFINITY ENERGY RELEASED WHEN AN ELECTRON IS ADDED TO AN ATOM INCREASES FROM LEFT TO RIGHT DECREASES FROM TOP TO BOTTOM

24 IE & AFFINITY TRENDS

25 REACTIVITY TRENDS METALS BECOME MORE REACTIVE DOWN THE GROUP NONMETALS BECOME LESS REACTIVE DOWN THE GROUP

26 ALKALI METAL PROPERTIES LOW DENSITY LOW MELTING POINTS GOOD CONDUCTORS OF ELECTRICITY SILVER IN COLOR SOFT +1 CATION

27 ALKALI METALS REACTIONS REACT EASILY WITH OXYGEN TO FORM OXIDES REACT EXOTHERMICALLY WITH WATER TO FORM STRONG BASES (METAL HYDROXIDES) AND H 2 GAS MUST BE STORED IN OIL TO PREVENT REACTION WITH O 2 COMBINE WITH HALOGENS TO FORM SALTS

28 HYDROGEN NOT AN ALKALI METAL IN SAME FAMILY DUE TO HAVING 1 VALENCE ELECTRON REACTS WITH HALOGENS BY SHARING ELECTRONS REACTS WITH ALKALI METALS BY FORMING A -1 ANION CALLED HYDRIDE

29 ALKALINE EARTH METAL PROPERTIES SIMILAR TO ALKALI METALS DO NOT NEED TO BE STORED IN OIL TO PREVENT REACTION WITH O 2 (FORM HARD OUTER LAYER THAT PREVENTS FURTHER REACTION) HARDER THAN ALKALI METALS +2 CATION

30 ALUMINUM FAMILY METALS AND METALLOIDS +3 CATION ALUMINUM IS MOST ABUNDANT METAL IN EARTH’S CRUST, FOUND AS OXIDE COMPOUND

31 CARBON FAMILY VARIETY OF PROPERTIES CARBON IS ONLY NONMETAL SILICON AND GERMANIUM ARE METALLOIDS TIN AND LEAD ARE MULTI-VALENCE METALS

32 ALLOTROPES DIFFERENT FORMS OF AN ELEMENT CARBON: GRAPHITE, DIAMOND, FULLERENES OXYGEN: O 2 AND O 3 PHOSPHORUS: RED AND WHITE

33 NITROGEN FAMILY N AND P ARE NONMETALS As AND Sb ARE METALLOIDS Bi IS METAL NITROGEN IS ESSENTIAL IN LIVING THINGS, PART OF DNA WHITE PHOSPHORUS BURSTS INTO FLAME IN OXYGEN

34 OXYGEN FAMILY MOST ARE NONMETALS (Po IS METALLOID) -2 ANION OXYGEN IS MOST ABUNDANT ELEMENT ON EARTH & 2ND MOST REACTIVE ELEMENT SULFUR KNOWN FOR BAD SMELLING COMPOUNDS & HAS MANY ALLOTROPES Se IS POOR CONDUCTOR IN DARK BUT GOOD IN LIGHT (LIGHT SENSITIVE)

35 HALOGENS NONMETALS -1 ANION BUT ALSO SHARE ELECTRONS DIATOMIC NOT FOUND IN ELEMENTAL FORM SINCE THEY ARE SO REACTIVE FORM SALTS WITH GROUP IA AND IIA TOXIC, USED TO KILL AND DISINFECT F IMPORTANT TO PREVENT TOOTH DECAY I IMPORTANT TO THYROID HEALTH

36 NOBEL GASES FULL VALENCE SHELL UNREACTIVE (INERT) GASES

37 TRANSITION METALS SOLIDS AT ROOM TEMP, EXCEPT Hg MOST ARE DUCTILE (PULLED INTO WIRE) MOST ARE MALLEABLE (CAN BE RE- SHAPED)