Test #2 By Weds Oct 21 at 11:00 Late deadline Thurs Oct 23 Vocabulary Quiz The deadline is 5PM on Friday Oct. 16 Will cover Chapters 10-17

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1 Test #2 By Weds Oct 21 at 11:00 AM Late deadline Thurs Oct 23 Vocabulary Quiz The deadline is 5PM on Friday Oct. 16 Will cover Chapters Schedule between now and then: Review: some today and more on Monday Oct 19 Friday 16. We will have a finish-up day. Melissa: Sat Oct W140 Benson Adrian: Monday 19 th 6-8 & Tues 20 th 7-9PM. Both are in B002 JFSB Chad M 19 th 5-7 in 446 MARB

2 Quiz: In the symbol below, what is the arrow pointing to? A. Chemical symbol B. Atomic number 52 Cr C. Mass number D. Ionic state Hint: look at the periodic table on wall. Elements are in order of atomic number.

3 Elements & Compounds Compounds: Substances made of two or more elements CdS PbS Cd S Pb S Elements: Substance made up of only ONE kind of atom

4 Alkali Metals The elements group together in families of similar chemical properties. At the left of the periodic table are the alkali metals: Lithium Li, Sodium Na, Potassium K, etc. All react energetically with water. Na K Rb Cs

5 Halogens The second column from the right is the halogens: Fluorine F, Chlorine Cl, Bromine Br, etc. Highly reactive. All form salt compounds

6 They don t let me do this, so we have to watch a movie.

7 Noble Gases At the right of the table are the noble gases: Helium He, Neon Ne, Argon Ar, etc. These do not easily combine with other elements.

8 Chemical properties can vary widely even when other physical properties are similar

9 Chemical properties can vary widely even when other physical properties are similar

10 Families of Elements Alkali Metals Noble Gases Halogens

11 Mendeleev Dimitri Ivanovich Mendeleev ordered the elements by atomic weight (mass number) and established that there were reoccurring patterns in the ways that elements combined with other elements. But the first attempt had a few problems. Order the elements by atomic number and the periodicity is perfect.

12 Quiz: Mendeleyev observed gaps in the patterns. Which hypothesis might reasonably explain the gaps? A. The properties were measured incorrectly. B. Some elements were not yet discovered. C. The patterns were only coincidental. D. Atomic weight was not the correct property upon which to base the pattern.

13 John Dalton proposed the atomic theory Matter is composed of small indivisible particles called atoms An element contains only a single kind of atom. Atoms of a given element are identical in every respect, including mass and chemical behavior. Atoms of different elements have different mass and chemical reactivity Chemical compounds are composed of two or more atoms that are joined together in fixed ratios Chemical reactions correspond to the rearrangement of atoms to form a different compound.

14 The wave model and the periodic chart To understand the main features of the periodic table we must use the wave model. It explains Atomic diameters Periodicities The octet rule for covalent bonding Molecular shapes

15 Wave Model and Periodic Table The wave model explains similar chemical properties by showing that all elements in a family have the same number of valence electrons in the same orbital types. The orbital type of valence electrons is the most important factor in determining how they behave.

16 The wave model & the periodic chart To understand the main features of the periodic table we must use the wave model. It explains Atomic diameters Periodicities The octet rule for covalent bonding Molecular shapes

17 Orbitals fill the lowest energy first. However, this does not always mean that the lowest shell is filled before electrons begin filling orbitals the next shell. Filling Orbitals

18 The orbitals of valence electrons s f d p

19 Wave Model & Periodic Table The wave model explains similar chemical properties by showing that all elements in a family have the same number of valence electrons in the same orbital types. The orbital type of valence electrons is the most important factor in determining how they behave.

20 Atomic Volume

21 Atomic Volume Atomic size suddenly increase at the beginning of each row then generally decrease across the row. smaller smaller

22 Quiz: What might account for the decreasing size of atoms as one moves across the periodic chart from left to right? A. The electrons get smaller. B. With more neutrons, the nucleus shrinks and so the whole atom shrinks. C. The additional protons provide more electric force to the outer electrons and pull their orbitals in more tightly.

23 Atomic Diameters Atomic diameters increase suddenly when the new electron is in the next shell As you move along the row, the outer electrons of elements have their electrons in the same shell; they fill different orbitals, but the diameters of orbitals in the same shell are comparable. However, more protons pulling on more electrons tends to squeeze the electron probability clouds in closer to the nucleus, decreasing the diameter.

24 Other Patterns Ionization energy: The energy required to strip an electron from the atom. etc freedom Ionization energy

25 Ionization Energies and the wave model Nobel gases have largest ionization energies. Alkali metals have the least.

26 Triumphs of the Periodic Table Predicted the existence of then undiscovered elements and what their chemical properties would be. Gave simplicity & order to chemistry. Firmly established the existence of atoms. Verified the wave model of the atom.

27 Now for some review

28 Chapter 10 Waves Types of waves Transverse (Shear) Longitudinal (Compression) Surface Properties of waves Wavelength Frequency Speed Amplitude Wave behavior Reflect ion Refrac tion Diffract ion Interference Standing Waves Nodes &

29 Chapter 11 Properties of Light Speed of Light How was it determined? Wave Nature of Light What experiments demonstrate this behavior? Diffraction and Interference Particle Behavior of Light Low light photography Photoelectric effect Relationship between Light & Energy

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31 Chapter 12 Properties of Matter States of Matter Solid, Liquid, Gas, Plasma Why are boiling and melting temperatures different for different materials? How does density relate to states of matter? Forces and Matter How does temperature affect the response of matter to force? Be able to read a data table and see what relationships may exist

32 Could you estimate the melting or boiling temperature for a material? Could you make a graph of melting & boiling temperatures? What would it look like?

33 Chapter 13 Molecular Model What was the Continuous Model of Matter? What are the 4 assumptions of the Molecular Model? Matter consists of tiny particles Different types of particles give different types of matter The particles are in constant motion (KE is T) Particles obey Laws of Motion, Conservation, Gravitation, & Electromagnetism How does the Molecular Model explain

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35 Chapter 14 Nuclear Atom Key experiments Gas discharge tubes Oil drop Gold foil Light spectra Models & their imperfections Plum pudding (Thompson) Solar system (Rutherford) Modified solar system (Bohr)

36 Chapter 15 Duality of Matter Experiments on Electrons Particle behavior Wave-like behavior When is the wave-like behavior important? What is the Heisenberg Uncertainty Principle? What is uncertain for small particles? Position Momentum

37 Chapter 16 Quantum model of atom There are no ORBITS! What is the quantum model Electrons are in orbitals Orbitals come in several types (s, p, d, f, ) Orbitals differ in energy; electrons have more E.P.E. in higher orbitals Each orbital can only have 2 electrons (Exclusion Principle) If 2 electrons are in an orbital, they differ in spin. Orbitals are grouped into shells

38 Chapter 17 Periodic Table Things that are PERIODIC Size Ionization Energy Formulae of Compounds Oxidation Number Valence Number Know why elements are arranged in Periods Groups

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40 Which of the following would tell me that an atom has 3 electrons in s and p orbitals in its outermost shell? A. Its row number in the periodic table B. Its mass number C. Its atomic number D. Its ionization energy E. Its valence number

41 Which of the following is most important in determining how the electrons behave? A. Amplitude of light (brightness) B. Speed of the light C. Charge on the photons of light D. Frequency of the light (related to energy of photons)

42 What if we changed from visible light to microwaves? Would we be able to remove electrons from the electroscope? A. Yes B. No

43 Which is the best description of molecules in a liquid? A. Fuzzy compressible balls that are in rapid motion B. Fuzzy compressible balls that are nearly at rest C. Particles moving randomly, but completely independent of all other particles D. Particles moving randomly with very weak bonding to other particles

44 In a vat full of liquid mercury, which of the following will increase as the temperature increases? A. Average electrical potential energy of the molecules B. Density of the liquid mercury C. Mass of the molecules D. Average kinetic energy of the molecules

45 At the same temperature, how do the speeds of molecules of different mass compare? A. More massive molecules have lower average speeds B. Less massive molecules have lower average speeds C. Mass has no effect on the average speed

46 If these are ripples on a pond, what type of waves are they? A. Transverse B. Surface C. Compression D. Torsion E. Longitudinal

47 The picture at the right is an interference pattern produced by passing many electrons through a thin layer of atoms and then capturing them on a screen. What would the picture look like if only one electron had been detected? A. A single bright dot B. Fewer bands of light and dark C. More bands of light and dark D. No change. The picture would look the same

48 Does this energy well diagram correctly show the orbitals in the first three shells around an atom? A. YES B. NO

49 What principle that we have discussed in class predicts that electrons will diffract and interfere in order to produce the pattern seen in the picture? A. Exclusion Principle B. Uncertainty Principle C. Law of Increasing Disorder D. Newton s Laws of Motion E. Universal Law of Gravitation

50 Nothing happens with visible light. Why? What can we do to get the electrons off? Why does UV light work?