ATOMS AND ELEMENTS UNIT 1: ST SCIENCE 9 ATOMIC MODELS PERIODIC TABLE OF ELEMENTS REPRESENTING MODELS

WHAT IS AN ATOM AN ATOM IS THE SMALLEST PARTICLE OF MATTER. IT CANNOT BE DIVIDED CHEMICALLY HOW SMALL IS AN ATOM? - A SHEET OF PAPER IS ABOUT A MILLION ATOMS THICK - A DROP OF WATER CAN CONTAIN MANY AS 10 SEXTILLION ATOMS. (10000000000000000000000) -THE DIAMETER OF THE PERIOD AT THE END OF THIS SENTENCE HAS 50 TRILLION ATOMS LINED UP IN A ROW IN IT. WHAT IS AN ATOM

ATOMIC MODELS DALTON’S MODEL 1808 SOLID BALLS. DIFFERENT COLORS. DIFFERENT MASSES CARBON OXYGEN ALL ATOMS OF THE SAME ELEMENT ARE THE SAME ALL ATOMS OF ONE ELEMENT ARE DIFFERENT FROM THOSE OF OTHER ELEMENTS ELEMENTS CAN COMBINE ATOMIC MODELS

ATOMIC MODELS THOMSON’S MODEL 1897 INCLUDED POSITIVE (PROTONS) AND NEGATIVE (ELECTRONS) CHARGES. ZINC COPPER - ADDED TO DALTON’S THEORY THAT ELEMENTS HAD BOTH POSITIVELY CHARGED AND NEGATIVELY CHARGED PARTS TO THEIR CORE ATOMIC MODELS

ATOMIC MODEL RUTHERFORD’S MODEL 1911 FIRST TO INTRODUCE THE NUCLEUS, LIGHTWEIGHT WITH NEGATIVE CHARGED ELECTRONS SCATTERED RANDOMLY IN A LARGE SPACE OUTSIDE THE NUCLEUS. BERYLIUM BERYLIUM ATOMIC MODEL

ATOMIC MODELS RUTHERFORD-BOHR MODEL 1913 SMALL NUCLEUS(PROTONS AND NEUTRONS), MORE CONSISTENT ELECTRONS IN A SERIES OF ORBITS. LITHIUM NICKEL ATOMIC MODELS

PERIODIC TABLE OF ELEMENTS

PERIODIC TABLE OF ELEMENTS METALS, NONMETALS, AND METTALOIDS METALS IDENTIFIED BY THE STAIRCASE SHAPED LINE THAT CROSSES THE RIGHT HAND SIDE OF THE TABLE. METALS: GOOD CONDUCTORS OF ELECTRICITY AND HEAT. MALLEABLE AND DUCTILE SO THEY CAN BE EASILY SHAPED. SHINY ROOM TEMPERATURE THEY ARE SOLIDS (EXCEPT MERCURY) THEY REACT WITH ACIDS PERIODIC TABLE OF ELEMENTS

PERIODIC TABLE OF ELEMENTS METALS, NONMETALS, METALLOIDS NONMETALS POOR CONDUCTORS OF ELECTRICITY AND HEAT MOST ARE GASES AT ROOM TEMPERATURE SOLID NONMETALS CAN BE REDUCED TO POWDER PERIODIC TABLE OF ELEMENTS

PERIODIC TABLE OF ELEMENTS METALS, NONMETALS, METTALOIDS METTALOIDS (ALSO CALLED SEMI-METALS) SEVEN ELEMENTS WITH PROPERTIES OF BOTH METALS AND NONMETALS. SOME CONDUCT WELL, SOME DON’T. FOR THIS REASON THEY ARE SEMI-CONDUCTORS USED IN TRANSITORS, INTEGRATED CIRCUITS, AND LASERS PERIODIC TABLE OF ELEMENTS

PERIODIC TABLE OF ELEMENTS GROUPS THEY CORRESPOND TO THE COLUMN IN THE PERIODIC TABLE. EACH GROUP SHARE A SET OF SIMILAR CHEMICAL PROPERTIES BECAUSE THEY ALL HAVE THE SAME NUMBER OF VALANCE ELECTRONS. VALANCE ELECTRONS (THE NUMBER OF ELECTRONS IN THE OUTERMOST SHELL) 2 – 8 – 8 – 18 ETC PERIODIC TABLE OF ELEMENTS

PERIODIC TABLE OF ELEMENTS GROUPS ALAKALI METALS ALL THE METALS OF THE 1ST GROUP. SOFT AND HIGHLY REACTIVE. IN PURE STATE, THEY MOST BE STORED IN OIL ALKALINE EARTH METALS ALL THE METALS IN THE 2ND GROUP. HIGHLY MALLEABLE AND BURN EASILY IN THE PRESENCE OF HEAT. HALOGENS NONMETALS IN GROUP 17. THEY REACT EASILY TO FORM COMPOUNDS (SALTS AND DISINFECTANTS) NOBLE GASES RARE GASES OR INERT GASES. LAST COLUMN. VERY STABLE. THEY REACT MINIMALLY PERIODIC TABLE OF ELEMENTS

PERIODIC TABLE OF ELEMENTS PERIODS CORRESPONDS TO THE ROW OF THE PERIDIC TABLE. ALL THE ELEMENTS HAVE THE SAME AMOUNT OF ELECTRON SHELLS HAVE CORRESPONDING REPETITION IN THE PATTERNS OF THEIR PROPERTIES (P. 23) MELTING POINT – TEMPERATURE OF SOLID TO LIQUID BOILING POINT – TEMPERATURE OF LIQUID TO GAS DENSITY – MASS PER UNIT OF VOLUME ATOMIC RADIUS – DISTANCE FROM CENTER OF THE ATOM FIRST IONIZATION ENERGY – ENERGY REQUIRED TO REMOVE OUTERMOST ELECTRON ELECTRONEGATIVITY – ATTRACTING TO FORM BOND PERIODIC TABLE OF ELEMENTS

PERIODIC TABLE OF ELEMENTS ATOMIC NUMBER REPRESENTS THE NUMBER OF PROTONS IN THE NUCLEUS OF AN ATOM ATOMIC MASS REPRESENTS THE RELATIVE MASS OF THE ATOM AN ELEMENT BASED ON CARBON’S 6 PROTONS AND 6 NEUTRONS MEASURING 12u ISOTOPES ADDED OR SUBTRACTED NEUTRONS DEPENDING ON THE ELEMENT PERIODIC TABLE OF ELEMENTS

REPRESENTING ATOMS LEWIS NOTATION (P. 27) A SIMPLER REPRESENTATION OF THE ATOM, IN WHICH ONLY THE VALENCE ELECTRONS ARE ILLUSTRATED. REPRESENTING ATOMS

REPRESENTING ATOMS RUTHERFORD-BOHR MODEL (P. 28) ALL THREE FACTS MUST BE REPRESENTED: 1- THE PERIOD (REPRESENTING THE NUMBER OF ELECTRON SHELLS IN THE ATOM) 2- THE GROUP (REPRESENTING THE NUMBER OF VALENCE ELECTRONS) 3- ATOMIC NUMBER(REPRESENTING THE NUMBER OF PROTONS AND ELECTRONS) REPRESENTING ATOMS

REPRESENTING ATOMS SIMPLIFIED ATOMIC MODEL (P. 28) WE ROUND THE MASS TO THE NEAREST WHOLE NUMBER. WE SUBTRACT MASS – ATOMIC NUMBER TO FIND HOW MANY NEUTRONS THERE ARE EXAMPLE: CHLORINE 35.45u = 35 35 – 17 = 18 THEREFORE 17 PROTONS 17 ELECTRONS 18 NEUTRONS REPRESENTING ATOMS

REPRESENTING ATOMS BALL AND STICK MODEL BALLS WILL MAKE UP THE ELEMENTS STICKS WILL MAKE UP THE BONDS REPRESENTING ATOMS