2. Energy and Periodic Trends

3. Topic: Periodic Table Trends Objectives: Day 1of 2 To understand the types of radiation To learn about ionization energy and how it relates to the periodic table To learn about electronegativity and how it relates to the periodic table Unit: Energy and Periodic Trends

4. Quickwrite Answer one of the questions below 1-2 sentences: If you recall, which group of the periodic table readily gives up electrons to form cations?? If you recall, which group of the periodic table readily gains electrons to form anions??

5. Atomic Properties Science is based on observations and discoveries For example, certain observations about substances will help us better understand our world We know that wood burns, steel rusts, plants grow, and sugar tastes sweet A better understanding of how atoms and molecules behave is crucial to helping us explore our natural world The periodic table is an important tool in helping us understand why atoms have predictable characteristic properties The objective is to understand the general trends or patterns in atomic properties in the periodic table

6. If you recall, the periodic table is divided into 3 basic different types of elements: -Metals -Semimetals -Nonmetals Metals, Semimetals, & Nonmetals

7. Nonmetals Semi MetalsMetals

8. 1- Anions1+ Cations2+ Cations2- Anions3+ Cations If you recall, group 1 metals like to lose an electron and group 2 metals like to lose an two electrons, becoming positively charged Non metals on the other hand, like to gain electrons and become negatively charged Atomic Properties & the Periodic Table

9. But what elements in group 1 are the most likely to lose an electron? Not all metals in group 1 behave exactly the same way For example, some metals can lose one or more electrons much more easily than others Cesium at the bottom of group 1, gives up an electron much more easily than lithium at the top of group 1 Atomic Properties & the Periodic Table Cesium loses an electron most easily Lithium is the least likely to lose an electron

10. In fact, as we go down the periodic table, the metals in group 1 become more likely to lose an electron Cs > Rb > K > Na > Li Atomic Properties & the Periodic Table Cesium loses an electron most easily Lithium is the least likely to lose an electron

11. Atomic Radius (Size) What do you notice about the relative sizes of the atoms as we move up group 1? That’s right the atomic radius gets smaller! Group 1 Period 4 What do you notice about the relative sizes of period 4 atoms as we move across the periodic table left to right? That’s right the atomic radius gets smaller!

12. Atomic Radius (Size) Atomic Size Decreases Atomic Size Decreases

13. Atomic Size Na MgAl Si P S Ar Cl Atomic Size Decreases Li Na K Rb Cs Atomic Size Decreases What makes the atomic size get bigger? Their nucleus and electron cloud size becomes larger

14. How does atomic Size Change across the Periodic table? Atomic size ________ as we go up the periodic table and decreases as we go left to right Their nucleus and electron cloud gets ________ Draw: Decreases Answer Bank Weakly larger Attract remove Decreases low decreases larger

15. Ionization Energies The ionization energy is the energy required to remove an electron from an individual atom Think of it as how easily an atom loses an electron Metals have low ionization energies, and nonmetals tend to have higher ionization energies

16. e- Sodium (Na) Atom P+ N N e- P+ N N N N N e- P+ N e- How much energy is required to remove an electron from a sodium atom? Recall that sodium likes to lose an electron to form a +1 ion In general, metals such as sodium have low ionization energies? 1+ Na + energy  Na +1 + e -

17. Ionization Energy What do you notice about the relative sizes of the atoms as we move up from cesium to Lithium? That’s right the atomic size gets smaller! Notice the Ionization Energy trend Ionization Energy Increases Ionization Energy Increases

19. What is Ionization Energy? The energy required to ______ an electron from an individual atom Metals (group 1 & 2) have _____ ionization energies and nonmetals (group 17 halogens & group 18 noble gases) have high ionization energies Draw: low Increases remove Answer Bank Weakly larger Attract remove Decreases low

20. Electronegativity If Ionization energy is how easily an atom loses an electron, then think of electronegativity as the exact opposite Electronegativity is the ability of an atom to attract electrons Think of it as the liking or attraction an atom has for an electron Nonmetals such as Flourine, chlorine and oxygen have high electronegativities In other words, Flourine, Chlorine and Oxygen love to steal electrons form other atoms

21. Electronegativity What do you notice about the relative sizes of the atoms as we move up from cesium to Lithium? That’s right the atomic size gets smaller! Notice the Electronegativity trend Electronegativity increases Electronegativity Increases

23. What is Electronegativity? The ability of an atom to _______electrons Think of it as the attraction an atom has for an electron Nonmetals such as Fluorine, Chlorine and Oxygen have high electronegativities along with noble gases such as Helium and argon Draw: attract Answer Bank Weakly larger Attract remove Decreases low Increases

24. Electronegativity vs. Ionization Energy P+ N N N N N N N e- P+ N Larger atoms lose Electrons easier because the outer electrons are farther from the nucleus, & are therefore more weakly held What determines Ionization energy and Electronegativity? The answer is atomic radius!

25. Electronegativity vs. Ionization Energy What determines Ionization energy and Electronegativity? The answer is atomic size! e- P+ N N N N N N N N e- Smaller atoms like fluorine hold their outer electrons are closer to the Nucleus and therefore do not Lose their electrons as easy This also enables them to steal Electrons from other atoms (High electronegativity)

26. The more Electronegative Atom, Fluorine in this case, steals the weakly held outer electrons from Cesium e- P+ N N N N N N N N e- P+ N N N N N N N e- P+ N Cesium Fluorine

27. How does atomic size effect ionization energy and electronegativity? Larger atoms (cesium) with low ionization energies ______ hold their outer electrons and therefore easily lose them Smaller atoms (fluorine) with high electronegativities strongly hold their electrons closer to the nucleus and therefore steal electrons from other atoms weakly Answer Bank Weakly larger Attract remove Decreases low

28. Summarize: List 3 atoms with a large atomic radius: Explain where atoms with low ionization energies can be found: List 3 examples: Explain where the most electronegative atoms can be found: List 3 examples: Explain where the largest atomic size can be found on the periodic table:

29. Topic: Energy and Light Objectives: Day 2 of 2 To understand different properties of light such as wavelength and frequency To understand how light is given off on the atomic level Unit: Light & Periodic Trends

30. Quickwrite Answer one of the questions below 1-2 sentences: How do you think atoms give off light???? What is radiation??? What are some different forms of radiation you might have heard of????

31. Energy and Light If you hold your hand a few inches from a brightly glowing light bulb what do you feel? Your hand gets warm! The light from bulb somehow transmits energy to your hand The same thing happens when you move close to the glowing embers of wood in a fire place The energy you feel from the sun is a similar example

32. Energy and Light In all 3 of these examples, energy is being transmitted from one place to another by light—more properly called electromagnetic radiation Many kind of electromagnetic radiation exist, including x-rays, used to penetrate your skin and produce images of your bones, microwaves to cook your food, and radio waves so you can call a friend on your cell phone

33. What is electromagnetic radiation? Energy transfer in the form of_______ Examples include: light, x-rays, radio waves, infrared (heat) waves Answer Bank Between Time excited packet Waves ground waves

34. Energy and Light How do these various types of electromagnetic radiation differ from one another? To answer this question we need to talk about waves Waves are characterized by 3 properties: wavelength, frequency and speed. The wavelength symbolized by the symbol lamda (λ) It is the distance between 2 consecutive wave peaks

35. Energy and Light How do these various types of electromagnetic radiation differ from one another? To answer this question we need to talk about waves Waves are characterized by 3 properties: wavelength, frequency and speed. The wavelength symbolized by the symbol lamda (λ) It is the distance between 2 consecutive wave peaks λ

36. What is wavelength? The distance ________ 2 consecutive wave peaks between Answer Bank Between Time excited packet Waves ground

37. The frequency of a wave (symbolized by the greek letter nu, ν) indicates how many times a peak passes by a point for a given time period Think of it as how many times the blue circle goes up and down every minute Energy and Light

38. The frequency of a wave (symbolized by the greek letter nu, ν) indicates how many times a peak passes by a point for a given _____ period (Think of it as how many times the blue circle goes up and down every minute) What is the frequency? time Answer Bank Between Time excited packet Waves ground

39. Energy and Light Light waves, x-rays, radio waves are all classified based on their wavelength Notice that x-rays have very short wavelengths, where as microwaves and radio waves have very long wavelengths

40. Radiation Link http://www.classzone.com/books/earth_sci ence/terc/content/visualizations/es2601/es 2601page01.cfm?chapter_no=visualizatio nhttp://www.classzone.com/books/earth_sci ence/terc/content/visualizations/es2601/es 2601page01.cfm?chapter_no=visualizatio n

41. Energy and Light The interesting thing about electromagnetic radiation is that it doesn’t always behave like as though it were a wave Sometimes electromagnetic radiation can have properties that are characteristic of particles

42. Energy and Light Another way to think of a beam light traveling through space is as a stream of tiny packets of energy called photons

43. What is photon? A “particle or _______ of energy” of electro magnetic radiation P acket Answer Bank Between Time excited packet Waves ground

44. Energy and Light So what is the exact nature of radiation and light? Is it a particle or wave? It seems both This situation is often referred to as the wave-particle nature of light

45. Energy and Light Different wavelengths of electromagnetic radiation carry different amounts of energy Shorter wavelengths carry less energy than longer wavelengths Is it a particle or wave? It seems both

46. Demo: Consider the results of the following demo/experiment I am going to dissolve compounds containing the Li + ion, Cu 2+ ion, and the Na+ ion in separate dishes containing methyl alcohol The solution or mixtures are then ignited Notice the brilliant colors that result

47. Demo: What causes the colors of these flames? The colors of these flames result from atoms releasing energy by emitting a specific wavelength which correspond to a certain color The heat from the flame causes the atoms to absorb energy We say the atom is excited! When the atom is excited, it gives off energy in the form of light

48. Energy levels of Helium An atom that it is excited can release energy in the form of light or photons An atom that is not excited is said to be in it’s ground state rather than it’s excited state

49. Helium Atom P+ N N e- Ground State (low energy level) Excited State (high energy level)

50. How does an atom give off light? An atom absorbs energy and becomes “_________” The electrons are now in an excited state (higher energy level) As electron return to their ______ state (low energy level), they give off light or photons The type of light (red or blue light) being emitted is dependent upon the difference in energy between the ground and excited states excited ground Answer Bank Between Time excited packet Waves ground

51. Summarize: List 3 different types of radiation: What’s the difference between wavelength and frequency: How is a photon different from a wave? In your own words, explain how light is given off on the atomic level:

53. Can I Remove More Than One Electron? A second, third, etc, electron can be removed from an atom. The ionization energies are termed accordingly: –2 nd Ionization energy to remove the 2 nd electron. –3 rd Ionization energy to remove the 3 rd electron.

56. 8.2 ns 1 ns 2 ns 2 np 1 ns 2 np 2 ns 2 np 3 ns 2 np 4 ns 2 np 5 ns 2 np 6 d1d1 d5d5 d 10 4f 5f Ground State Electron Configurations of the Elements