1. Who demonstrated lightning is electric? 2. Father of the periodic table = GET YOUR NOTES OUT!!! Day

1.Put the three people / events in chronological order (first to last): Dalton, discovery of the electron, Democritus Day

Jigsaw  11 minutes to write group notes!  Rest of the period to share with other groups.

Do NOT eat yet!!! 1. You are allowed to eat this cookie in chem. because it represents _______________ model. In which the chocolate chips represent ____________ and the rest of the cookie represents ____________. Day

Jigsaw Review and keys Chronological order

Atoms defy what we thought we knew! 1902 Ernest Rutherford and Frederick Soddy discovered that radioactivity produces new __________ Nuclear decay of uranium- 238 elements

238 U → + 4 He Th uranium-238 → thorium α particle Atomic # Mass #

Mass # = protons + neutrons Atomic # = protons – periodic table Write the nuclear symbol for Carbon with 6 neutrons Write the nuclear symbol for Carbon with 8 neutrons

Write the nuclear symbol for Boron with 6 neutrons F 9 19 The atom of fluorine represented below: Protons = Neutrons = Atomic number = Mass number =

1. Draw the nuclear symbol for bromine-80. atomic # = protons = mass # = neutrons = Day

What does the inside of an atom look like and how do we know? Day

Atoms defy what we thought we knew! Ernest Rutherford’s –Experiment applet #1Experiment applet #1 –Experiment applet #2Experiment applet #2

Ernest Rutherford’s Atom’s appearance: –____________________ –____________________________________ –________________________________ Hollow sphere Dense center with positive charge Electrons occupy empty space

Atoms defy what we thought we knew! Neils Bohr - modified Rutherford’s atomic model. –Electrons are located in _______ ______ ______. Used this model to explain _________ __________ energy levels emission spectra specific

Atoms defy what we thought we knew! Neils Bohr - modified Rutherford’s atomic model. –When an electron becomes excited (gains energy) it can jump up to a new energy level. When it falls back down to its ground state it emits energy (light).

Atoms defy what we thought we knew! 1913 Frederick Soddy coined the term _______ –Atoms of the same ________ –Differ in ____ –Differ in ___________ –Examples ________________________ _________________________ isotope element mass radioactivity Carbon-12 and Carbon-13 Uranium-236 and Uranium-238

Atoms defy what we thought we knew! 1913 Henry Moseley –Assigned ______ ________ to each element –Realized that something in the _______ of an atom determines … atomic numbers nucleus

Atoms defy what we thought we knew! 1913 Henry Moseley –Realized that something in the _______ of an atom determines its position on the _______ _____. nucleus Periodic Table

1. Draw the nuclear symbol for carbon-14. atomic # = protons = mass # = neutrons = Day

What does the inside of an atom look like and how do we know? Day

Atoms defy what we thought we knew! 1919 Ernest Rutherford discovered _______ –Carry a _______ charge and are found in the ______. –The number of _______ is the atom’s ______ _______. protons positive nucleus protons atomic number

Atoms defy what we thought we knew! 1926 Neils Bohr’s ________model of the atom –_–______ _____ –_–_______ is dense center with ______ _______ –_–________ found in specific energy levels quantum Empty sphere Nucleus protons Electrons positive

Neils Bohr’s ________model of the atom –________ found in specific energy levelsquantum Electrons Atoms defy what we thought we knew! 1926

Atoms defy what we thought we knew! 1932 James Chadwick discovered _________ –Have no _______ –Located in the atom’s _______ neutrons charge nucleus

3( ) Atoms defy what we thought we knew! 1938 Lise Meitner was the first to correctly describe a nuclear ________ reaction in which a large nucleus is split into two smaller nuclei of approximately equal size. 235 U + 1 n → → 141 Ba + 92 Kr + fission U 1 0 n U

Today: Is matter continuous or discontinuous? What are protons, neutrons, and electrons made of? What about string theory? quarks, bosons, muons, gluons, etc! Is there a tiniest piece of energy that everything is made of?

Today: Is matter continuous or discontinuous? When you ask “What is the smallest piece?”, be certain to specify what you want! –Cmpd. = –Element = –Atom = Is there a tiniest piece of energy that everything is made of? group of bonded atoms single atom ??

Parts of Atoms, Isotopes, and Ions Isotopes –Atoms of one element Same number of _______ Different numbers of ________ Different ______ protons neutrons masses

Parts of Atoms, Isotopes, and Ions Ions –________ atoms that have gained or lost ________ –Examples Iron loses 2 electrons Chlorine gains 1 electron Charged electrons Fe +2 Cl -1

Assignment # 1 Unit 3 MAKE UP WORK!!! Assignment: #s 26, 27, 30, 31 on page 119