Catalyst – February 7-1, 2012 HW OUT! Grab a calculator too! Monday Mystery Element! (copy clues, then make guess) 1. It is a metal. 2. Its name comes from Lithos, Greek for stone. 3. It is used in batteries.

Catalyst – February 7-1, 2012 Monday Mystery Element! 1. It is a metal. 2. Its name comes from Lithos, Greek for stone. 3. It is used in batteries. LITHIUM!!!

Today’s Agenda  Catalyst  Unit 1 Test Results/Tracking/Lab Fees  HW/Atomic Math Challenge Review  Atomic Theory Day 1  Notes, Get Know’d on Rays of the Cathode  Exit Question HW: Workbook pages 47-48

Today’s Objectives  SWBAT create their first Chemistry Hood Resume.  SWBAT distinguish between atoms using atomic math and isotopes.  SWBAT describe/trace the evolution of the atomic theory from 420 B.C. to 1898.

Describe 1 of the 12 Testing Power Words!  Example: Describe a way to improve your school or community  Tell all about  Give a detailed account  Characterize

Unit 1 Test Domination Stats Class Mastery Averages 2 nd Period: 84.3% SO close! 3 rd Period: 78.0%  5 th Period: 75.7 

Unit 1 Test Masters 85% or Above Mastery, 2 nd Period Jasmine Barnes Luke Belile Nila Belton Jayson Camus Bryana Clark Blake Dominick Jasmine Gusman Chris Hebert Russell Holloway Deanna McCann Sherell Sparks Arielle Stevenson William Taylor Kevin Thomas

Unit 1 Test Runners-Up % Mastery, 2 nd Period Jenna Bonnet Jenna Burke Lindsay Chartier Banika Claiborne Marolinka Conley Andrew Davis Tra Fisher Jorrance Mitchell

Unit 1 Test Masters 85% or Above Mastery, 3 rd Period Mecalla Balmas Ryan Craigie Layla Early Josh Hayes Temika Isidore Joie Kinney Jaymie Mayberry Kayla Melanson Destiny Rhea Allie Rivero Joey Rivero Lauren Smith Dominick Taylor

Unit 1 Test Runners-Up % Mastery, 3 rd Period Kevin Austin Demirr Farlough Cory Gillespie Briana Myles Megan Rivet Nikki Williams Jasmine Young

Unit 1 Test Masters 85% or Above Mastery, 5 th Period Sharika Arceneaux Keiara Bailey Kathy Berroa Jesus Buendia Aerial Davis Jornell Jones Alesia McCoy Blake Ronquille Alex Wells Myderika Willis

Unit 1 Test Runners-Up % Mastery, 5 th Period Chyna Black Taylor Bourgeois Ashley Bowman Roxy Camardelle Molly Jenkins Antione LaGarde Titus Jones Larriane Schuster Torien Seals Champagne Wysingle

Unit 1 Test Champs  1 st Place (107): Josh Hayes  2 nd Place (103): Jasmine Gusman  3 rd Place (102): Layla Early

Test Tracking/Resume  Go through test  Count number of points CORRECT for each GLE  Calculate percent mastery by dividing CORRECT points by the POSSIBLE POINTS and then multiplying that decimal by 100  Draw a line graph to show mastery  Check off or get sticker if you got 85% or above mastery

Re-Mastery Assignment  Must be completed by Thursday, 2/9, in order to participate in Thursday’s Flame Test Lab  If you did NOT achieve mastery on the GLEs below, you must complete the worksheet (worth 100 Participation Points)  2 nd and 3 rd Period GLEs: SI 1 and PS 1  5 th Period GLEs: SI 3, PS 2, PS 1  If you DID achieve mastery on GLEs above, you do not have to complete worksheet but can for 50 Bonus Points

Atomic Math Challenge Key Points  Key Point #1: The three main subatomic particles are protons, neutrons, and electrons.

Atomic Math Challenge Key Points  Key Point #2: The identity of an element depends on the atomic number, which is always equal to the number of protons. Atomic number = # p +

Atomic Math Challenge Key Points  Key Point #3: The mass of an atom = the number of protons plus the number of neutrons. Atomic Mass = # p + + # n 0 # n 0 = Atomic Mass - # p +

Atomic Math Challenge Key Points  Key Point #4: Since all atoms are neutral in their natural state, the number of protons = the number of electrons.

Isotope Challenge Review  Isotopes are atoms that have the same number of protons but different numbers of neutrons  This means that the atoms are of the same element but have different masses

Atomic Math Challenge Key Points  Key Point #5: Because isotopes of an element have the same atomic number, or number of protons but different numbers of neutrons they also have different mass numbers.

Review of Homework (Workbook pages 52-54) 1. $ mL g 4. Element A: 62.4%; element B: 32.9%; element C: 4.7% 5. B 6. Ask Ms. Stroh 7. Mass number

Review of Homework (Workbook pages 52-54) 10. Ask Ms. Stroh 11. Neon , 12, An atom of neon-22 has two more neutrons in its nucleus than an atom of neon Isotopes 15. True 16. B 17. C 18. A

Review of Homework (Workbook pages 52-54) 19. The values of atomic masses measured in grams are inconveniently small and impractical to work with. 20. Carbon-12; 12 amu 21. False 22. A, C 23. A

GUIDED NOTES TIME! ATOMIC THEORY DAY ONE!!!

Review of Last Week’s Notes HypothesisConclusionTheoryLaw Pre- explanation (tentative) Post- explanation (after experiment) Explanation supported by many experiments Explanation of natural phenomena One scientist More than one scientist Sooooo many scientists Experiments must still be conducted Experiment has been conducted (but not a theory yet!) Has taken a long time to develop Has taken a loooong time to develop from theories

What is an atom? Atom: the smallest part of an element that retains (keeps) the properties of the element

Well then, what is an element? Element: a pure substance that cannot be broken down into simpler substances by physical or chemical means NOT THIS KIND OF ELEMENT

Well then, what is an element? Element: a pure substance that cannot be broken down into simpler substances by physical or chemical means NOT THIS KIND OF ELEMENT

Well then, what is an element? THESE KINDS OF ELEMENTS

Why is the atom so important? The atom is the building block of all matter! Without atoms, our universe would no exist!

Essential Questions for Unit 2 1) What are the most important contributions to the development of atomic theory? 2) What makes one atom different from another? How are atoms similar? 3) Why is it so important to understand how the periodic table is organized? 4) What secrets can we uncover about the elements using the periodic table?

Atomic Theory  Atomic theory is the theory we will focus on in Chemistry  It is theory of the nature of matter (stuff)  Tells us that all matter is composed of atoms  The specifics of the theory have change a lot  Why is atomic theory considered a theory instead of a fact?  Why do you think the theory changed throughout history?

Major Playas of Atomic Theory Democritus ( B.C.) John Dalton (1808) J.J. Thomson (1897) Ernest Rutherford (1909) Niels Bohr (1913) Schrodinger (1924)

Acceptance of Scientific Discovery “Cliff’s Notes”  Use the following rules of evidence to examine experimental results: A. Can it be/has it been tested? B. Has peer review occurred? C. What kind of error does it have? D. Were there standards or control groups? E. Has it been accepted by scientific community?

Democritus ( B.C.)  Experiment: Observations and inferences  No REAL experiment…just IDEAS  Where: Greece  When: 420 B.C.  First “theory” of the atom

What were Democritus’ conclusions? Matter is composed of tiny particles called atomos Different kinds of particles have different sizes and shapes Atoms are indivisible and indestructible

In the beginning…  Around 420 B.C. Democritus, a Greek philosopher, was the first to think of the idea of atoms  A philosopher is a thinker  Around the same time Aristotle, a more famous philosopher, proposed a different idea.

In the beginning…  Aristotle gave us this quote…  Among other things…  He challenged the ideas of Democritus  He did not think the “nothingness” of empty space could exist “We are what we repeatedly do. Excellence, therefore, is not an act but a habit.”

Questions to Ponder…  Why was Democritus’ idea not a theory?

John Dalton ( ) Experiment: Careful chemical measurements Where: England When: 1808

Then came along…  In 1808, John Dalton came up with the first atomic theory that was based on scientific research.  It stated: 1. All matter is made of atoms. 2. Atoms are indivisible and indestructible. 3. All atoms of a given element are identical in mass and properties 4. Compounds are formed by a combination of two or more different kinds of atoms. 5. A chemical reaction is a rearrangement of atoms.

What were Dalton’s conclusions? Atoms are hard, round, solid balls. They are similar to marbles.

Questions to Ponder…  Why would people believe John Dalton and not Democritus?  What makes John Dalton’s ideas about the atom a theory and Democritus’ ideas a thought?

Questions in the 1800s…  What is the relationship between matter and electrical charge?  What happens if electricity passes through ‘empty’ glass tubes?

Cathode Rays  Cathode rays were a stream of negatively charged particles  It was concluded that these negative particles were found in all forms of matter (these are now known as electrons)  J.J. Thomson began a series of measurements…

J. J. Thomson ( ) Experiment: Cathode ray tube When: 1897 Where: England

Thomson’s Cathode Ray Experiment  Passed electric current through gases at low pressure  Shot a beam of electrons (cathode ray) from one end of a tube to the other

Thomson’s Cathode Ray Experiment  Found that a cathode ray is attracted to a positively charged plate and is deflected (repelled) by a negatively charged plate -- +

Credited with discovering the electron Electrons have a very, very small mass; therefore, they must be smaller than atoms The atom is, in fact, DIVISIBLE Atoms have parts of them that are negatively charged What were Thomson’s conclusions?

J.J. Thompson’s New Model  The new model was called the Plum Pudding Model  Plum pudding is like a chocolate chip cookie  The negative particles floated in a sea of positive charge like chips in the cookie dough Plum Pudding Model Dalton’s Model

Thomson was pretty hungry when… Now I have finished my model! It looks like Plum Pudding!

Question to Ponder…  If Atoms have parts of them that are negatively charged and…  Scientists knew from before that atoms are neutral (no charge)  What can scientists infer about atoms?

More Discovery!  1866: Evidence for a POSITIVELY charged particle, called the PROTON.  1932: Existence of another subatomic particle called the NEUTRON with NO (OR NEUTRAL) charge.

Exit Question 1. Why was Dalton’s theory of the atom more valid than Democritus’? 2. Why was Thomson’s contribution to atomic theory so important? HW: Workbook pages Turn in Friday's HW and Today's Resume!