Use your jigsaw notes: Day Which atomic model showed the probable locations of electrons? 2.Which atomic model was the first to show the nucleus of an atom? 3.Which atomic model was first to show energy levels?

Investigated _________ and its behaviors. The chemical properties of radioactive elements _______ as radiation is emitted. radiation change We have Atoms! – 1898 Marie Skłodowska Curie and Pierre Curie

Isolated and discovered the elements _________ and ________. polonium radium We have Atoms! – 1898 Marie Skłodowska Curie and Pierre Curie

We have Atoms! – 1899 Ernest Rutherford Analyzed ________ to determine its ___________. –______________, , are fairly heavy with a ________ charge. –_____________, , are very tiny with a ________ charge. radiation composition Alpha particles positive Beta particles negative

We have Atoms! – 1899 Ernest Rutherford –_____________, , are very tiny with a ________ charge. –____________, , have no mass with a _______ charge. Beta particles negative Gamma rays neutral

Radiation Penetration

Radiation Separation What does this separation pattern indicate about charges and masses of these types of radiation? –α: ______ mass and ________ charge –β: ________ mass and _________ charge largerpositive smallernegative

What does this separation pattern indicate about charges and masses of these types of radiation? –β: ________ mass and _________ charge –γ: ___ mass and ___ charge smallernegative nono Radiation Separation

Atoms defy what we thought we knew! Max Planck realized that atoms _________________. have their own rules Good-bye, Newtonian physics! Hello, Quantum Physics!

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

Atoms defy what we thought we knew! 1902 Nuclear decay of uranium U → + 4 He Th uranium-238 → thorium α particle Atomic # Mass #

Use your notes: Day Which type of radiation is the most dangerous (penetrating)? 2.Which type of radiation is made up of high speed electrons?

Read pages and answer #s 9-15 on page 109

Atoms defy what we thought we knew! 1902 Nuclear decay of uranium 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

Practice For Neon with 9 neutrons: Mass #? _____ # of protons? _____ atomic #? _____ Write the nuclear symbol: 19 10

Practice If an atom has 7 protons + 9 neutrons: Mass #? _____ element = ? _________ atomic #? ____ Write the nuclear symbol: 16 nitrogen 7

Practice Uranium-239: Mass #? _____ protons? ____ atomic #? ____ Write the nuclear symbol:

Practice If an atom has 17 protons + 18 neutrons: Mass #? _____ element = ? __________ atomic #? ____ Write the nuclear symbol: 35 chlorine 17

Assignment # 1 Unit 3

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 weight 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

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 ______ _______. –Conducted the first _______ ____________ reaction, … protons positive nucleus protons atomic number artificial transmutation

Atoms defy what we thought we knew! 1919 Ernest Rutherford discovered _______ –Conducted the first _______ ____________ reaction, changing the element __________ into the element ________ protons artificial nitrogen-14 oxygen-17 transmutation 14 N + 4 He → + 1 H O 17 8

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 levels –Formula for the maximum number of e - per level:quantum Max # e- = 2n2 n = number of energy level 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

Page 104 #s 1-4 Read pages and answer #s 9-15 on page 109