ELEMENTS AND THE PERIODIC TABLE

Agenda I. Organizing the Elements II. Metals III. Nonmetals IV. Where Elements Come From

I. ORGANIZING THE ELEMENTS

A) THE FIRST PERIODIC TABLE

1) MENDELEEV MADE UP CARDS WITH EACH ELEMENT a) DENSITY b) ATOMIC MASS c) COLOR d) MELTING POINT e) BONDING POWER

2) MENDELEEV ARRANGED THE ATOMS BY INCREASING MASS a) NOTICED A PATTERN IN BONDING POWER b) BROKE OFF AT REPEATING BONDING POWERS c) OBSERVED PATTERN IN COLUMNS d) ADJUSTED A COUPLE TO MAKE COLUMN PATTERNS CONSISTENT

3) MENDELEEV PREDICTED “MISSING” ELEMENTS a) ADJUSTING FOR PATTERN CAUSED THREE “HOLES” IN TABLE b) MENDELEEV PREDICTED ELEMENTS TO FIT IN “HOLES” c) BASED ON PATTERN, PREDICTED PROPERTIES OF THOSE ELEMENTS

d) WITHIN 16 YEARS THESE ELEMENTS WERE DISCOVERED SCANDIUM GALLIUM GERMANIUM

B) THE MODERN PERIODIC TABLE IN THE EARLY 1900’S THE STRUCTURE OF THE ATOMS WAS FURTHER DEFINED

1) ATOMS HAVE THREE PARTICLES a) PROTONS - IN THE NUCLEUS, + CHARGE b) NEUTRONS - IN THE NUCLEUS, 0 CHARGE c) ELECTRONS - OUTSIDE THE NUCLEUS, - CHARGE

2) EACH ELEMENT HAS A DIFFERENT NUMBER OF PROTONS; THE NUMBER OF PROTONS IS CALLED THE ATOMIC NUMBER

THE PERIODIC TABLE WAS REARRANGED SLIGHTLY SO THAT IT IS NOW IN ORDER OF INCREASING ATOMIC NUMBER INSTEAD OF INCREASING ATOMIC MASS

C) THE USE OF THE PERIODIC TABLE EACH SQUARE CONTAINS: ATOMIC NUMBER CHEMICAL SYMBOL NAME ATOMIC MASS

1) ORGANIZATION OF THE TABLE AN ELEMENT’S PROPERTIES CAN BE PREDICTED FROM ITS LOCATION IN THE PERIODIC TABLE

a) GROUPS VERTICAL COLUMNS ARE CALLED GROUPS OR FAMILIES ELEMENTS IN THE SAME FAMILY HAVE SIMILAR CHARACTERISTICS

b) PERIODS HORIZONTAL ROWS ARE CALLED PERIODS ELEMENTS ACROSS A ROW VARY GREATLY IN THEIR PROPERTIES

2) WHY THE PERIODIC TABLE WORKS THE PERIODIC TABLE ALLOWS US TO PREDICT AN ELEMENT’S CHEMICAL BEHAVIOR

a) BONDING POWER RECALL THAT MENDELEEV ORGANIZED HIS TABLE BY REPEATING BONDING POWERS; HE DID NOT KNOW ABOUT ELECTRONS

b) VALENCE ELECTRONS 1) THE ELECTRONS THAT GOVERN CHEMICAL BONDING ARE CALLED VALENCE ELECTRONS 2) THESE ELECTRONS ARE SHARED OR TRANSFERRED IN CHEMICAL REACTIONS 3) ELEMENTS IN THE SAME GROUP HAVE THE SAME NUMBER OF VALENCE ELECTRONS, THEY INCREASE FROM LEFT TO RIGHT

1 8 2 3 4 5 6 7

II METALS

A) PROPERTIES OF METALS

1) PHYSICAL PROPERTIES a) HARDNESS b) SHININESS c) MALLEABILITY d) DUCTILITY e) CONDUCTIVITY MAGNETIC

2) CHEMICAL PROPERTIES SOME METALS ARE VERY REACTIVE (Na, K) OTHERS ARE NOT VERY (Au, Cr) REACTIVE METALS TEND TO BE TO THE LEFT ON THE PERIODIC TABLE

B) FAMILIES OF METALS

1) ALKALI METALS a) GROUP 1 b) VERY REACTIVE c) NEVER FOUND ALONE IN NATURE d) ONE VALENCE ELECTRON

2) ALKALINE EARTH METALS a) GROUP 2 b) REACTIVE c) NEVER FOUND ALONE IN NATURE d) TWO VALENCE ELECTRONS

3) TRANSITION METALS - GROUPS 3-12 a) HARD AND SHINY b) VERY SIMILAR TO EACH OTHER c) TEND TO REACT, BUT NOT VERY RAPIDLY d) GOOD CONDUCTERS OF ELECTRICITY

4) METALS IN MIXED GROUPS METALS IN GROUPS 13-16 ARE IN FAMILIES WHICH CONTAIN A MIX OF METALS, NONMETALS, AND METALLOIDS. THEY ARE NOT VERY REACTIVE

5) LANTHANIDES AND ACTINIDES a) FOUND IN PERIODS 6 AND 7, BETWEEN THE ALKALINE EARTH METALS AND THE TRANSITION METALS b) VERY SIMILAR TO EACH OTHER c) ONLY Th AND U ARE FOUND IN ANY ABUNDANCE d) USED IN ALLOYS

III NONMETALS AND METALLOIDS NONMETALS ARE SEPARATED FROM METALS WITH A BOLD ZIG-ZAG LINE. METALLOIDS ARE THOSE ELEMENTS WHICH HAVE A SIDE TOUCHING THE ZIG-ZAG LINE

A) PROPERTIES OF NONMETALS

1) PHYSICAL PROPERTIES a) DULL b) BRITTLE c) NOT MALLEABLE d) NOT DUCTILE e) POOR CONDUCTORS

2) CHEMICAL PROPERTIES a) READILY FORM COMPOUNDS (EXCEPT GROUP 18) b) EITHER GAIN OR SHARE ELECTRONS TO FORM COMPOUNDS 1) WHEN NONMETALS JOIN TO METALS, ELECTRON(S) MOVE FROM THE METAL TO THE NONMETAL 2) WHEN TWO NONMETALS JOIN, THEY SHARE ELECTRONS 3) WHEN TWO NONMETALS OF THE SAME TYPE JOIN, THEY ARE CALLED A DIATOMIC MOLECULE

B) FAMILIES OF NONMETALS

1) THE CARBON FAMILY- GROUP 14, 4 VALENCE ELECTRONS, CARBON IS THE MAIN ELEMENT OF LIFE

2) THE NITROGEN FAMILY -GROUP 15, 5 VALENCE ELECTRONS, NITROGEN IS THE PRIMARY COMPONENT IN AIR, NECESSARY FOR LIVING THINGS

3) THE OXYGEN FAMILY - GROUP 16, 6 VALENCE ELECTRONS, OXYGEN IS EXTREMELY REACTIVE

4) THE HALOGEN FAMILY - GROUP 17, 7 VALENCE ELECTRONS, VERY REACTIVE, FORM SALTS

5) THE NOBLE GASES - GROUP 18, DON’T INTERACT WITH OTHERS, FULL SHELL OF ELECTRONS

6) HYDROGEN - TOO DIFFERENT TO BE IN ANY FAMILY, BUT HAS ONE VALENCE ELECTRON

C) THE METALLOIDS ON THE BORDER BETWEEN METALS AND NONMETALS ARE SEVEN METALLOIDS. VARYING ABILITY TO CONDUCT ELECTRICITY - SEMICONDUCTORS (Si AND Ge)

IV WHERE THE ELEMENTS COME FROM

A) ATOMIC NUCLEI COLLIDE 1) PLASMA - NUCLEI STRIPPED OF ELECTRONS (HIGH SPEED) 2) NUCLEAR FUSION - COMBINING OF NUCLEI (ENERGY RELEASE)

B) ELEMENTS FROM THE SUN HYDROGEN ATOMS COMBINE TO MAKE HELIUM, ETC. ELEMENTS UP TO IRON CAN BE MADE THIS WAY IN A STAR

C) ELEMENTS FROM LARGE STARS ELEMENTS HEAVIER THAN IRON REQUIRE MASSIVE AMOUNTS OF ENERGY. THIS ENERGY OCCURS WITH THE SUPERNOVA EXPLOSION