2.  Smallest part of an element with all the properties of that element.  2 parts

3.  Center of atom  most of atomic mass  contains protons & neutrons Nucleus

4. 5 B Boron 10.81 Mass  Mass # = Mass of the nucleus  1 proton = 1amu (atomic mass unit)  1 neutron = 1 amu  The average # protons + # neutrons  Electrons too small to contribute to mass

5. 11NaSodium22.9924CrChromium51.9936KrKrypton83.80 Na = 23 Cr = 52 Kr = 84 A.11 B.23 C.22.99 D.22 A.24 B.51 C.51.99 D.52 A.36 B.83 C.83.80 D.84

6.  Cloud of electrons that surrounds the nucleus  Individual electrons move so fast, they appear as a cloud  Most of the volume of the atom.  Mostly empty space. - - Electron Cloud

7. 1. Protons: positive charge (+) located in nucleus 2. Neutrons: neutral charge (=) located in nucleus 3. Electrons: negative charge (-) located in the electron cloud

8.  # protons (positive charges) = atomic #  Atoms of different elements have different numbers of protons. 5 B Boron 10.81 + + + + + = = = = = = - - - - - Atomic Number

9. 11NaSodium22.9924CrChromium51.9936KrKrypton83.80 Na = 11+ Cr = 24+ Kr = 36+ A.36 B.83 C.83.80 D.84 A.24 B.51 C.51.99 D.52 A.11 B.23 C.22.99 D.22

10.  Which atom has 8 protons?  Which atom has 6 protons?  Which atom has 7 protons? A. CarbonB. Nitrogen C. OxygenD. Moccium6CCarbon12.017NNitrogen14.008OOxygen15.99Oxygen Carbon Nitrogen

11.  # neutrons (neutral, no charge) = mass – protons (atomic #) 5 B Boron 10.81 + + + + + = = = = = = - - - - - Atomic Number (# protons) Mass (# protons + # neutrons 11 (rounded) -5 6 neutrons

12. 11NaSodium22.9924CrChromium51.9936KrKrypton83.80Na23-11 12 = 12 = Cr52-24 28 = 28 =Kr84-36 48 = 48 = A.11 B.12 C.22.99 D.22 A.24 B.26 C.28 D.52 A.36 B.48 C.83.80 D.84

13.  # electrons (negative) = # protons (atomic #)  # negative charges = # positive charges, the atom is neutrally charged (has no charge) 5 B Boron 10.81 + + + + + = = = = = = - - - - - Atomic Number

14. 11NaSodium22.9924CrChromium51.9936KrKrypton83.80 Na = 11- Cr = 24- Kr = 36- A.36 B.83 C.83.80 D.84 A.24 B.51 C.51.99 D.52 A.11 B.23 C.22.99 D.22

15. 13 Al Aluminum 26.98 1. How many protons (+) does an atom of Aluminum have? 2. How many electrons (-) does an atom of Aluminum have? 3. How many neutrons (=) does an atom of Aluminum have? 27 (mass #) -13 (atomic #) 14 = 14 = 13 - 13 + A.13B. 14 C. 26D. 27 A.13B. 14 C. 26D. 27 A.13B. 14 C. 26D. 27

16. 12 Mg Magnesium 24.31 1. How many protons (+) does an atom of Magnesium have? 2. How many electrons (-) does an atom of Magnesium have? 3. How many neutrons (=) does an atom of Magnesium have? 24 (mass #) -12 (atomic #) 12 = 12 = 12 - 12 + A.12B. 13 C. 24D. 25 A.12B. 13 C. 24D. 25 A.12B. 13 C. 24D. 25

17. 15 P Phosphorus 30.97 1. How many protons (+) does an atom of Phosphorus have? 2. How many electrons (-) does an atom of Phosphorus have? 3. How many neutrons (=) does an atom of Phosphorus have? 31 (mass #) -15 (atomic #) 16 = 16 = 15 - 15 + A.15B. 16 C. 30D. 31 A.15B. 16 C. 30D. 31 A.15B. 16 C. 30D. 31

18. Element Atomic # Mass # Protons+Neutrons=Electrons-Boron511 Neon2010 Fluorine910 5 56 101010 9 19 9 How many protons (+), neutrons (=), and electrons (-) does an atom of Boron have? A.5 (+), 5(=), 5(-)B. 11(+), 11(=), 11(-) C. 5 (+), 6(=), 5(-)D. 5(+), 11(=), 5(-) What is the atomic # of Neon, and how many protons (+) and neutrons (=) does an atom of it have? A.At#10, 20(+), 10(=)B. At#10, 10(+), 10(=) C. At#20, 10(+), 10(=)D. At#10, 10(+), 20(=) What is the atomic # and mass of Fluorine, and how many electrons (-) does an atom of it have? A.At#10, mass 19, 10(-)B. At#19, mass 9, 9(-) C. At#9, mass 10, 9(-)D. At#9, mass 19, 9(-)

19.  # shells = # of ROW on Periodic Table 5 B Boron 10.81 + + + + + = = = = = = - - - - - 2 nd Row 2 Energy Levels

20.  1 st Shell = No more than 2  2 nd Shell = No more than 8  3 rd Shell = No more than 8  Last Shell = # of COLUMN on Periodic Table 5 B Boron 10.81 + + + + + = = = = = = - - - - - 5 Electrons 2 Electrons in 1 st shell B is in 3 rd Column  3 electrons in last shell

21.  Teacher demonstrates diagramming atoms with atomic #1, #2, #3, #10, #18  Students work with partners – one sheet of paper per team.  Take turns diagramming the atoms. While one draws, the other checks work.  One person diagrams the odd numbered elements, partner checks work.  The other person diagrams the even numbered elements, partner checks work.