1 / 29

UNIT 1 – MATTER AND QUALITATIVE ANALYSIS

UNIT 1 – MATTER AND QUALITATIVE ANALYSIS. OBJECTIVES. To understand the difference between observation and inference To understand the difference between theoretical and empirical knowledge To explain the development of the atomic model

grahamt
Télécharger la présentation

UNIT 1 – MATTER AND QUALITATIVE ANALYSIS

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. UNIT 1 – MATTER AND QUALITATIVE ANALYSIS

  2. OBJECTIVES • To understand the difference between observation and inference • To understand the difference between theoretical and empirical knowledge • To explain the development of the atomic model • To describe the relationship between atomic number, atomic mass, and the different subatomic particles • To relate observations and inferences and describe real world examples

  3. Building Scientific Knowledge • Observation and Inference • Observation: Statement that is based on what you see, hear, taste, touch and smell • Inference: A judgment or opinion that is based on observations and/or conclusions • Integral part of qualitative analysis • When trying to identity matter, scientists firs observed the sample, then they infer based on their observations and comparing to known matter

  4. TASK: THE BURNING CANDLE • Materials: Candle, match, ruler, timer • Obtain a candle, match and watch glass • Light the candle ad drip some wax on the watch glass. Place the candle upright in the hot wax and secure it. • Observe the candle for 5 minutes • Write down as many statements as possible about the burning candle • Divide the statements into two categories: observations and inferences • Compare the number of observations to the number of inferences

  5. Extension • Provide ONE example of an observation and ONE example of an inference that could be stated by each of the following: • A nurse examining a patient with a high fever • A chef tasting a new recipe • A paramedic arriving at the scene of an accident • A firefighter sifting through the debris of a recently extinguished fire

  6. Empirical and Theoretical Knowledge • Empirical Knowledge: knowledge coming directly from observations • Theoretical Knowledge: knowledge based on ideas that are created explain observations • Theory: an explanation of a large number of related observations

  7. Models • Model: representation of a theoretical concept • Help to visualize a theory and suggest ways to test the theory

  8. Homework • Page 12: #1-3

  9. Early Atomic Models (Text Ref. 1.3) • Atom: the smallest particle on an element that has all the chemical properties

  10. Dalton’s Atomic Theory (1803) • All matter consists of definite particles called atoms • Each element is made up of its own type of atom • Atoms of different elements have different properties • Atoms of two or more elements can combine in constant ratios to form new substances • Atoms cannot be created, destroyed or subdivided in a chemical change

  11. Dalton’s Model (Billiard Balls)

  12. Subatomic Particles - Electrons • 1897: J. J. Thomson used cathode ray tubes to examine gas discharge • Observed: All gases emitted beams that behaved the same under magnets • Inferred: There must be particles within all atoms that are the same and are negatively charged • Later: names electrons

  13. Thomson’s Model • “The Raisin Bun” model: • + and – charges are mixed together • Gave us electrons: Electrons are negatively charged • Atoms can gain or lose electrons to form ions

  14. Rutherford’s Experiment

  15. Anticipated: Actual:

  16. Rutherford’s Model Electrons Protons Neutrons

  17. Explanation • The atom is made of a dense core (nucleus) with positively charged protons and neutral neutrons • Electrons orbit around the nucleus • The number of protons determines the element’s identity • The number of electrons equals the number of protons in NEUTRAL elements

  18. Isotopes • Elements with the same number of protons but a different number of neutrons are called isotopes • Masses are averaged on most periodic tables • Example: Carbon • 6 proton; 6 electrons • Most carbon atoms have 6 neutrons: Carbon-12 • Some have 7 neutrons: Carbon-13 • Some have 8 neutrons: Carbon-14

  19. SUMMARY OF SUB-ATOMIC PARTICLES

  20. The Periodic Table: An Introduction • The Periodic Table is an incredibly useful tool that organizes all known elements into columns and rows according to their chemical and physical properties • Elements 1-92: Elements that are found naturally on earth (except 43) • Elements 93-117: Not stable, made in particle accelerators • Group: columns • Period: rows • Metals are on the right; Non-metals are on the left; Metalloids are on the jagged line going down the left hand side

  21. Some Specifics: • Main Group Elements: Groups 1-2, 13-18 • Alkali Metals: Group 1 (extremely reactive metals) • Alkaline Earth Metals: Group 2 • Halogens: Group 17 (very reactive non-metals) • Noble Gases: Group 18 (non-reactive gases) • Transition Metals: Groups 3-12 • Lanthanides: Top row of the bottom section • Actinides: Bottom row of the bottom section

  22. Periodic Tables - Activity • On the blank periodic table, colour code each section, label them • Metals • Non-metals • Metalloids • Alkali Metals • Alkaline Metals • Transition Metals • Lanthanides/Actinides • Halogens • Noble Gases

  23. Periodic Tables • Tell you a lot of information • Elements in the same groups have similar bonding properties and reactivity patterns • Elements in the same periods have similar sizes • As you increase in number on the periodic table, you increase in atomic mass • They often contain the following information: • Atomic Number • Atomic Mass • Electronegativity • Element Charges

  24. Determining #Protons, Electrons, Neutrons • Atomic Number (P): Number of Protons • # p = # e- • Atomic Mass (M): Number of Protons (P) + Number of Neutrons (N) • M = P + N

  25. Example • Determine the number of protons, neutrons and electrons in neutral a. Iron-56 b. Bismuth-209

  26. Atomic Symbols Z Mass Number: M P Atomic Number:

  27. Homework: • Page 15 #2,3,4,6 • Worksheet: Protons, Neutron, and Electrons

  28. I CAN: • Understand the difference between observation and inference • Understand the difference between theoretical and empirical knowledge • Explain the development of the atomic model • Describe the relationship between atomic number, atomic mass, and the different subatomic particles • Relate observations and inferences and describe real world examples

  29. Next Class: • Quiz: Observation/Inference, Theoretical/Empirical, Periodic Table, Atomic Models, Electrons/Protons/Neutrons • Required: Name of Element for Element Assignment • Topics: Electromagnetic Spectrum, Bohr’s Model, Chemical Bonding

More Related