Starter: Quick Review

1. Starter: Quick Review • How many minutes are in 2 weeks? • Express the answer to 10.5m + 12.15m in correct sig figs • Express 525K in degrees Celcius • The mass of a sample of salt is 20kg. The density of the salt is 4g/cm3. What is the volume of the sample of salt in mL?

2. As you come in, • The Materials: • Paper and pencil for notes • ½ sheet of paper • History timeline • Pick up packet. • The Plan: • Discuss your Unit One tests (return ASAP) • Learn about basic atomic structure • Homework: • Complete the Atomic Structure Numbers Worksheet • NOTE: Models of the Atom, Isotopes, Atomic Mass &, Atomic Structure Numbers Quiz on Monday

3. Starter: Let’s Jog Your Memory • So…what is an atom? • Draw a diagram of an atom labeling the following parts: nucleus, electron cloud, proton, electron, neutron • Describe the 3 subatomic particles (Ex: location, charge, mass, etc)

4. Back to the Reading • Who theorized that all matter is composed of fire, air, water, and earth? • Name the famous Greek philosopher who agreed with the theory described above. • Name the scientist who established the Law of Conservation of Matter. • Name the famous Greek philosopher who disagreed with #1 and said that matter could be broken down into “atomos.” • Who said that “All atoms of a given element are identical.”?

5. Atomic Theory • History of the Theory: • Early ideas of the atom • Democritus • Aristotle • John Dalton (pg. 56)

6. Atomic Theory • History of the Theory: • Early ideas of the atom • Democritus - “atomos”; atoms exist • Aristotle - atoms do NOT exist • John Dalton (pg. 56) - 2000 years later; atoms exist • Matter is made up of atoms. • Atoms are indivisible. • Atoms of same (different ) elements are same (different) • LAW OF CONSERVATION OF MATTER

7. More Recent Atomic Theory • JJ Thomson • Found Electrons through the cathode ray experiment • E. Rutherford Nucleus in gold foil experiment (Protons travel in different directions when they hit the nucleus)

8. Modern Atomic Theory • Neils Bohr First atomic model to show Energy levels • Schrodinger • Sublevels & orbitals

9. Subatomic Particles

10. Proton Significance • Gives the atom its identity • Equivalent to the atomic number • Massive particle so adds to the atom’s mass • Gives the nucleus its positive charge • Balances the negative charge of the electrons

11. Neutron Significance • Neutron glue that holds the nucleus together • Massive particle so adds to the atom’s mass (mass number= p + n) • Number can differ from one atom to another giving isotopes

12. Electron Significance • Responsible for chemical properties • Forms ions when gained or lost, which leads to a charge

13. Atomic Number • The picture is NOT completely correct. • Atomic # IS the number of protons in the atom. It is NOT always the number of electrons. • Therefore, the atomic # gives the atom its identity...its name.

14. Atomic Number • In isotopic notation, the atomic number is shown in the lower left corner of the element symbol. • Example: 6C

15. Atomic Number- Quick Check • If an atom is found to have 28 protons, what is its identity? • What is the atomic number of phosphorus? • How many protons does barium have? • Show the following elements in “isotopic notation”: • Lithium, sodium, sulfur, lead

16. Atomic Number- Quick Check • If an atom is found to have 28 protons, what is its identity? Ni = Nickel • What is the atomic number of phosphorus? 15 • How many protons does barium have? 56 • Show the following elements in “isotopic notation”: • Lithium, sodium, sulfur, lead

17. Charge • Charge = oxidation state • Oxidation state is just a fancier way to say it. • A charged atom results from an inequality between protons and electrons in an atom. • Which of those particles (protons or electrons) are more likely to be gained or lost from an atom? Why?

18. Charge Example • Example: Bromine has 35 protons. It often gains electrons to other atoms. If Bromine gains an electron, the atom will have 36 electrons. What will the charge be? • Answer: -1 charge

19. Charge...Now , you try • Example: Calcium has 20 protons. It often loses electrons to other atoms. If calcium loses 2 electrons, the atom will have only 18 electrons. What will the charge be? • Answer: +2 charge

20. Charge • In symbolic notation, the charge is listed in the top right corner of the element symbol. If the charge is neutral, then the corner is left blank. • Question: What does Cl-1 means for the amount of protons and electrons for a chlorine atom? • Answer: protons = 17 (don’t change), electrons = 18 (gained one)

21. ChargeQuick Check • What is the charge of sulfur when it gains 2 electrons to the neutral atom? • Write the symbolic notation to represent an atom of aluminum that has lost 3 electrons leaving 13 protons and 10 electrons. • How many protons and electrons are in the following atom? Cu 2+

22. ChargeQuick Check • What is the charge of sulfur when it gains 2 electrons to the neutral atom? S-2 • Write the symbolic notation to represent an atom of aluminum that has lost 3 electrons leaving 13 protons and 10 electrons. Al3+ • How many protons and electrons are in the following atom? Cu 2+ 29P, 27E

23. Mass Number • Consider the subatomic particles. Which TWO particles have enough mass to matter? • Mass number is always a whole number...no decimals. • Mass number is calculated by adding the number of protons to the number of neutrons.

24. Mass Number • In symbolic notation, the mass number is shown in the upper left corner of the element symbol. • Example: 126C **Important Equations**

25. Mass NumberQuick Check • If a sodium atom has 11 protons and 12 neutrons, what is the atom’s mass number? • How many neutrons does a copper atom with a mass number of 64 have? • How many protons and neutrons are in the atom represented with this symbolic notation: 3216S

26. Isotopic Notation Summary • Shorthand way to record the element symbol, atomic number, charge, and mass number. • With this information, you can deduce the number of protons, neutrons, and electrons in the atom being represented. X Mass # Charge Atomic #

27. Starter: Atomic Structure • Isotopes of the same element have different numbers of _________ in their atom but the same number of _______. • ________ do not affect the atom’s mass but determine the oxidation state. • How many protons, electrons and neutrons are in the following atom? 58 Cerium-140 Write the correct isotopic notation for the element that has 26 protons, 30 neutrons, and 23 electrons.

28. Take 10…Finish Up • Complete at least 4 stations in the gallery walk • Isotopic Notation must be complete (atomic #, atomic number) • The assignment will be turned in for a grade today • If you finish early, take out your Unit 2 review packet that you received yesterday and work on the Atomic Number WS • Please ask if you have any questions

29. Atomic Structure: Part II • Students will understand… • The difference between mass number and atomic mass • How to calculate average atomic mass and relative abundance

30. Blocks on the Table • PROTONS give an atom its identity. They are the ONLY subatomic particle that must be identical from one atom to another. Neutrons AND electrons can vary... • SO, how can we create ONE box on the periodic table to represent ALL atoms of an element? We must represent AVERAGE atoms. (That’s why the atomic mass has decimals.)

31. Atomic Mass • Atomic mass = the weighted average of all of the types of atoms (isotopes) of the element • Must know the % abundance (how much of it is found in nature relative to other isotopes) and the mass number • Check out the example!

32. Atomic Mass Example • Copper exists as a mixture of 2 types of atoms. The lighter copper has 29 protons and 34 neutrons, and it makes up 69.17% of all copper atoms. The heavier type has 29 protons and 36 neutrons. It makes up the remaining 30.83% of copper on earth. What is the atomic mass of copper?

33. Atomic Mass Example • Element Z exists in 3 isotopic forms. The isotopic mixture consists of 15% Z-16, 35% Z-17, and Z-18 makes up the remaining percent. What is the atomic mass of this element?

34. Relative Abundance Calculation • Element X has two naturally-occurring isotopes with isotopic weights of 10 and 12. You look on the periodic table to find that its average atomic mass = 10.5 What is th relative and percentage abundance of each isotopes?

35. Relative Abundance Calculation • Silver has two naturally-occurring isotopes with isotopic weights of 106.90509 and 108.90470. What is the relative and percentage abundance of each isotopes?

36. Starter: AM Review • Element M exists in 3 isotopic forms. The isotopic mixture consists of 20% M-10, 50% M-15, and M-20 makes up the remaining percent. What is the atomic mass of this element? • Chlorine has two isotopes. Chlorine-35 has an exact weight 34.968852 amu, and it has a 75.77% abundance. The other isotope has 36.965903 amu. What is the atomic mass?

37. Isotope/Atomic Mass Lab • You and your partner will analyze a sample of the element Candium. • Gather the data, and calculate the atomic mass of candium. • You can eat your sample at the end! 8-) • Work on the new atomic mass calculations ws at your desk when you are done.

38. Isotope/Atomic Mass Lab • Important Information: • You can write on the sheet provided • Be sure to keep correct sig figs after measuring the mass • Keep your candy on a paper towel if you plan to eat them • Straighten up your lab area when you are finished • Be sure to stay on task…the assignment is graded!

39. Starter • Hydrogen has two naturally-occurring isotopes with isotopic weights of 1.007825 and 2.014102. What is the relative and percentage abundance of each isotope? • True or False: • Isotopes of an atom have different numbers of protons. • Although atoms are mostly empty space, they still have mass.

40. Energetic Electron • Electrons are energetic, and they exist on energy levels. • Quantum: specific amount of energy needed to move from one energy level to the next; energy levels are given principal quantum numbers as a result • When electrons change energy levels, energy is absorbed and released. • Light is sometimes visible when the energy is released (Emission of Light)

41. Quantum Illustration Quantum = distance between two energy levels Principal Quantum Number (n) = begin counting closest to the nucleus

42. Quantum Illustration • Principal Quantum number (n): • Refers to the principal energy level, which tells you the amount of energy the electron has • The CLOSER the electron is to the NUCLEUS the LESS energy it has

43. Quantum Leap Illustration An electron from n=2 (ground state) can absorb a quantum of energy and jump to n=3 (excited state). Excited state is temporary. The electron will soon release the quantum and fall back from the higher level to ground state. EMISSION OF LIGHT can occur and the released energy will travel as a wave.

44. Electromagnetic Spectrum(All energy waves fall into one of these categories.)

45. Electromagnetic SpectrumLet’s see if you get it…wavelength vs frequency

46. Calculating the Emission of Energy • Two Equations to calculate the energy: • Speed of light = wavelength x frequency c = λν c = 3.0 x108 m/s (speed of light is constant) 2. Energy = Planck’s constant x frequency E = hν h=6.626x10-34Jsec (Planck’s constant)

47. iRespond Question Multiple Choice F Finding a Connection Look at the two equations. What variable do they have in common? A.) Speed of light (c) B.) Wavelength (lambda) C.) Frequency (nu) D.) Energy (E) E.)

48. Electromagnetic Wave Calculations • So, if I know the _______ of a wave, then I can calculate its wavelength AND its energy.

49. Energy Practice Problem: If the wavelength is 0.001 meters, then what is the frequency of the wave? iRespond Question Multiple Choice F A.) 300,000 Hz B.) 3.0x1011 Hz C.) 3.33x10-12 Hz D.) 6.626x10-37 Hz E.)

50. Energy Practice Problem: If the wavelength is 0.001 meters, then what is the energy of the wave? iRespond Question Multiple Choice F A.) 1.99x10-22 J B.) 2.21x10-45 J C.) 1.99x1046 J D.) 6.626x10-37 J E.)