Chemeketa Community College Chapter 3: Atoms & Elements Larry Emme Chemeketa Community College

Mixtures & Pure Substances Electron Energy Levels Chapter Outline Mixtures & Pure Substances Elements & Symbols The Periodic Table Atomic Structure Isotopes Electron Energy Levels

Matter Weight on earth. The stuff things are made of. Has Mass and takes up space. (Air, water, rocks, etc..) The amount of stuff (in g’s) (Bowling Ball > Balloon) Matter: The stuff things are made of. Has Mass and takes up space. Mass: The amount of stuff. Usually measured in grams. Bowling ball has more mass than Weight on earth. Weight on earth. Pull of Gravity on matter.

Classification of matter Pure Substance Mixture Element Compound Fe FeS Fe + S Mg MgO Mg + O2

Mixtures Air Pizza Urine Gasoline Tea w/ice Sand Mixture Homogeneous (Solution) Heterogeneous Non-uniform composition Uniform composition Pizza Gasoline Tea w/ice Air Fe + S Urine Sand

American Periodic Table

Atomic Symbols Each element is assigned a unique symbol Nitrogen Hydrogen Nickel Aluminum Bromine Each element is assigned a unique symbol 1-2 letters; 1st is capitalized

Atomic Symbols Some of the elements whose symbols are derived from other languages Copper (Cuprum) Cu Gold (Aurum) Au Iron (Ferrum) Fe Lead (Plumbum) Pb Mercury (Hydrargyrum) Hg Potassium (Kalium) K Silver (Argentum) Ag Sodium (Natrium) Na Tin (Stannum) Sn Tungsten (Wolfram) W

Atomic Symbols Carbon Copper (Cu) Calcium Cobalt Chlorine Chromium Elements with same starting letter, get second letter added to the symbol

Periodic Table: Groups (Families) Alkali Metals (exclude H) Noble (Inert) gases Alkaline Earth Metals Halogens I A VIIIA H He II A III A IV A V A VI A VIIA Li Be B C N O F Ne Transition Metals Na Mg Al Si P S Cl Ar III B IVB V B VIB VIIB VIII B IB IIB K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn Fr Ra Ac Gd Cm Tb Bk Sm Pu Eu Am Nd U Pm Np Ce Th Pr Pa Yb No Lu Lr Er Fm Tm Md Dy Cf Ho Es

Periodic Table: Periods Periods are assigned numbers H He 1 2 3 4 5 6 7 Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn Fr Ra Ac Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr

Metals Lustrous, malleable and ductile. Conductors (heat & electricity) Solids at room temp (except Hg) Lose electrons to non-metals. H He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn Fr Ra Ac Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr

Non-metals Gas, liquid, solid (dull, brittle) H He Li Be At Te As Si B C N O F Ne Na Mg Al P S Cl Ar Gas, liquid, solid (dull, brittle) Poor conductors = Insulators Many are diatomic molecules. Gain e’s from metals Share e’s with other non-metals K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge Se Br Kr Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb I Xe Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po Rn Fr Ra Ac Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr

Metalloids Intermediate properties Semi conductors H He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe Intermediate properties Semi conductors Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn Fr Ra Ac Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr

Metals Non-metals Metalloids H He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn Fr Ra Ac Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr

Atom - The smallest unit of an element that is still that element. A model of matter Atom - The smallest unit of an element that is still that element. ie. Aluminum (Al) Molecule -The smallest unit of a pure substance that is still that substance. May contain > 1 atom or element. ie. Water (H2O)

protons Structure of the atom & neutrons Nucleus = Small, dense, + charge in the center of an atom. + contains protons + + + + + & neutrons

- charged particles that surround the nucleus. Structure of the atom Nucleus Electrons - charged particles that surround the nucleus. Electrons move around the nucleus in orbits (orbitals).

Structure of the atom The nucleus is a small part of an atom. If the nucleus was the size of a marble, the atom would fill a football stadium. The nucleus would weigh over 10,000 tons.

X - - - - - - The atomic symbol A = Mass number (amu) = # protons + # neutrons - - X A - - Z + + Z = Atomic number = # protons = # electrons (if neutral) - + + + + -

X - - - - - - 6 The atomic symbol A = Mass number 12 Z = Atomic number = # protons + # neutrons 6 - - 6 X 12 - - 6 + + Z = Atomic number = # protons = # electrons (if neutral) - + + + + -

C - - - - - - 6 The atomic symbol A = Mass number 12 Z = Atomic number = # protons + # neutrons - - C 12 - - 6 + + Z = Atomic number = # protons = # electrons (if neutral) - + + + + -

Na Sodium The atomic symbol A = Mass # = p + n = 23 23 11 Z = Atomic # = p = 11 Sodium

Why is the atomic weight on the tables not a whole #? 47 Atomic number Name of the element Elemental Symbol Silver Ag 107.87 Atomic mass (weight) Atomic weight = The average, relative mass of an atom in an element.

- - - Isotopes of Hydrogen H H H + + + Isotopes = Atoms of the same element but having different masses. 1 2 1 3 1 H H H - - - + + + Protium 99.99% Tritium Trace % Deuterium 0.01%

Average Atomic weight of Hydrogen Isotopes of Hydrogen Isotopes = Atoms of the same element but having different masses. 1 2 1 3 1 H H H - - - + + + H-1 or Hydrogen-1 H-2 or Hydrogen-2 H-3 or Hydrogen-3 Average Atomic weight of Hydrogen = 1.00794 amu

Average Atomic weight of C= 12.011 amu Isotopes of Carbon C-12 or Carbon-12 C-13 or Carbon-13 C-14 or Carbon-14 12 13 14 C C C 6 6 6 - - - - - - - - + + + - + + + + + + + + + - - + + + + + + - - - - - - - 98.89% 1.11% Trace % Average Atomic weight of C= 12.011 amu

So falls apart (decays) Giving radioactive particles Radioactive Isotopes 14 3 1 C H 6 - - - - + + + + + - + + - - Nucleus is unstable So falls apart (decays) Giving radioactive particles

The atomic symbol & isotopes Determine the number of protons, neutrons and electrons in each of the following. 15p,16n, 15e 56p,82n, 56e 92p,146n, 92e 31 15 138 56 238 92 P Ba U 24 12 19 9 Mg+2 F-1 12p,12n, 10e 9p,10n, 10e

Atomic Structure ____ ____ ____ 4 5 ___ Be 4 9 4 17 17 20 17 Symbol At# Mass P N e– ____ ____ ____ 4 5 ___ Be 4 9 4 Cl ____ 37 ___ ___ ___ 17 17 20 17 Si ____ ____ ___ 14 ___ 14 28 14 14

fill layers around nucleus Electron arrangement 24 12 Mg Electrons fill layers around nucleus Low  High 32 18 A new layer is added for each row or period in the table. 8 2 Shells = Energy levels

IA IIA 1 H 4 2 He 7 3 Li 9 4 Be

IA IIA IIIA 1 H 11 5 B 7 3 Li 9 4 Be

IIIA IVA VA 11 5 B 12 6 C 13 7 N

H He Be Li Ne Mg Ar Na 1 4 2 9 4 7 3 IA IIA VIIIA 20 10 23 11 24 40 12 18 Ar 23 11 Na

H Be Li B Mg Al Na 1 9 7 4 3 1 Valence electrons Where most chemical Reactions occur. 1 H 2 3 9 4 Be 7 3 Li 11 5 B 24 12 Mg 27 13 Al 23 11 Na Inner electrons: No reactions if normal conditions.

Inner vs. valence electrons This is where most chemical reactions occur. Inner electrons Not much happens here under normal conditions. With added energy inner electrons jump to higher levels, then fall back giving E

1 8 1 H 4 2 He 2 9 4 Be 20 10 Ne 7 3 Li 24 12 Mg 40 18 Ar 23 11 Na

H Li Na K H Li Lewis Structures Show only Valence Electrons Na 1 7 3 23 11 Na K 1875-1946

The End

End of Chapter Learning Checks Try these after you have reviewed the chapter

Learning Check The element potassium is in the first group on the Periodic Table (group IA). Potassium is a. an alkali metal b. an alkaline earth metal c. a transition element d. a halogen

Learning Check Answers The element potassium is in the first group on the Periodic Table (group IA). Potassium is a. an alkali metal b. an alkaline earth metal c. a transition element d. a halogen

Learning Check The elements on the periodic table are placed in order of increasing Density Atomic number Boiling point Atomic mass

Learning Check Answers The elements on the periodic table are placed in order of increasing Density Atomic number Boiling point Atomic mass

Learning Check A solid sample of an unknown element is dull and brittle and does not conduct heat or electricity. How should the element be classified? Metal Nonmetal Metalloid Transition element

Learning Check A solid sample of an unknown element is dull and brittle and does not conduct heat or electricity. How should the element be classified? Metal Nonmetal Metalloid Transition element

Learning Check The majority of the elements are Metals Gases Nonmetals Metalloids

Learning Check Answers The majority of the elements are Metals Gases Nonmetals Metalloids

Learning Check Which is not a metalloid? Boron (B) Silicon (Si) Germanium (Ge) Aluminum (Al)

Learning Check Answers Which is not a metalloid? Boron (B) Silicon (Si) Germanium (Ge) Aluminum (Al)

Learning Check Which of the following is not a diatomic element? Fluorine Oxygen Nitrogen Carbon

Learning Check Answers Which of the following is not a diatomic element? Fluorine Oxygen Nitrogen Carbon

Learning Check Which of the following nonmetals is not reactive? Helium Fluorine Oxygen Carbon

Learning Check Answers Which of the following nonmetals is not reactive? Helium Fluorine Oxygen Carbon