This document summarizes key concepts about atomic structure and the periodic table. It introduces the periodic table and describes the properties and organization of elements in groups and periods. It then discusses atomic structure models including the Thompson, Rutherford, Bohr, and quantum mechanical models. Finally, it covers periodic trends in atomic radius, ionization energy, and electronegativity as well as formation of ions, isotopes, and average atomic mass.

1. Chemistry SOL Review by Anne Mooring (Jamestown High School, Williamsburg VA, 2006) Part 2: Atomic Structure and Periodic Relationships Parts of the Periodic Table Introduction to the SOL Periodic Table Atomic Structure and the Periodic Table Periodic Trends in Atomic Radius, Ionization Energy, and Electronegativity. Isotopes and Average Atomic Mass Historical and Quantum Models of the Atom A calculator will be helpful, but not necessary for this powerpoint. This section represents 8/50 of the SOL questions

2. The columns are called groups or families. Groups have similar physical and chemical properties and the same number of valence electrons

3. Name the groups boxed in yellow, orange, green and blue.

4. Name the groups boxed in yellow, orange, green and blue. Alkali metals, Alkaline Earth metals, Halogens, and Noble or Inert Gases.

5. The rows are called periods. The period number matches the principle energy level of the element. This will be the principle energy level of the valence electrons.

6. What is the principle energy level of Nickel, Ni?

7. What is the principle energy level of Nickel, Ni? 4—it is in the row numbered 4

8. Using the SOL Periodic Table Click on the link to get the SOL periodic table Keep this Adobe file open as you work on the review Let’s use the periodic table to answer some questions about Silicon Chemistry SOL Review—Atomic Structure

9. Using the SOL Periodic Table Let’s use the periodic table to answer some questions about Silicon. How many protons does Silicon have? Chemistry SOL Review—Atomic Structure

10. Using the SOL Periodic Table Let’s use the periodic table to answer some questions about Silicon. How many protons does Silicon have? 14 protons = atomic number. How many electrons does neutral Silicon have? Chemistry SOL Review—Atomic Structure

11. Using the SOL Periodic Table Let’s use the periodic table to answer some questions about Silicon. How many protons does Silicon have? 14 protons = atomic number. How many electrons does neutral Silicon have? 14 electrons (# electrons = # protons in neutral atoms) How many neutrons does Silicon-30 have? Chemistry SOL Review—Atomic Structure

12. Using the SOL Periodic Table Let’s use the periodic table to answer some questions about Silicon. How many protons does Silicon have? 14 protons = atomic number. How many electrons does neutral Silicon have? 14 electrons (# electrons = # protons in neutral atoms) How many neutrons does Silicon-30 have? 16 neutrons. Silicon-30 is an isotope of Silicon. It has a mass number of 30. The mass number is protons + neutrons. Chemistry SOL Review—Atomic Structure

13. Using the SOL Periodic Table Let’s use the periodic table to answer some questions about Silicon. How many protons does Silicon have? 14 protons = atomic number. How many electrons does neutral Silicon have? 14 electrons (# electrons = # protons in neutral atoms) How many neutrons does Silicon-30 have? 16 neutrons. Silicon-30 is an isotope of Silicon. It has a mass number of 30. The mass number is protons + neutrons. What is the molar mass of Silicon? Chemistry SOL Review—Atomic Structure

14. Using the SOL Periodic Table Let’s use the periodic table to answer some questions about Silicon. How many protons does Silicon have? 14 protons = atomic number. How many electrons does neutral Silicon have? 14 electrons (# electrons = # protons in neutral atoms) How many neutrons does Silicon-30 have? 30 neutrons. Silicon-30 is an isotope of Silicon. It has a mass number of 30. The mass number is protons + neutrons. What is the molar mass of Silicon? 28.0855 grams/mole (this is the same as the atomic mass on the periodic table) Chemistry SOL Review—Atomic Structure

15. Using the SOL Periodic Table Let’s use the periodic table to answer some questions about Silicon. How many protons does Silicon have? 14 protons = atomic number. How many electrons does neutral Silicon have? 14 electrons (# electrons = # protons in neutral atoms) How many neutrons does Silicon-30 have? 30 neutrons. Silicon-30 is an isotope of Silicon. It has a mass number of 30. The mass number is protons + neutrons. What is the molar mass of Silicon? 28.0855 grams/mole (this is the same as the atomic mass on the periodic table) How many valence electrons does Silicon have? Chemistry SOL Review—Atomic Structure

16. Using the SOL Periodic Table Let’s use the periodic table to answer some questions about Silicon. How many protons does Silicon have? 14 protons = atomic number. How many electrons does neutral Silicon have? 14 electrons (# electrons = # protons in neutral atoms) How many neutrons does Silicon-30 have? 30 neutrons. Silicon-30 is an isotope of Silicon. It has a mass number of 30. The mass number is protons + neutrons. What is the molar mass of Silicon? 28.0855 grams/mole (this is the same as the atomic mass on the periodic table) How many valence electrons does Silicon have? 4 valence electrons. Look for electrons in the highest principle energy level. Chemistry SOL Review—Atomic Structure

17. Chemistry SOL Review—Atomic Structure An s orbital holds 2 electrons w/ opposite spins

18. Chemistry SOL Review—Atomic Structure Each p orbital holds 2e- with opposite spins

19. Chemistry SOL Review—Atomic Structure Each d orbital holds 2e- with opposite spins

20. Chemistry SOL Review—Atomic Structure The s suborbital fills The orbitals and the periodic table

21. Chemistry SOL Review—Atomic Structure The p suborbitals fill The orbitals and the periodic table

22. Chemistry SOL Review—Atomic Structure The d suborbitals fill The orbitals and the periodic table

23. Chemistry SOL Review—Atomic Structure Valence electron configuration and the periodic table All group 13 elements have the valance electron configuration ns 2 np 1 .and 3 valence electrons

24. Chemistry SOL Review—Atomic Structure Valence electron configuration and the periodic table All group 15 elements have the valance electron configuration ns 2 np 3 .and 5 valance electrons.

25. Chemistry SOL Review—Atomic Structure Valence electron configuration and the periodic table What is the valence configuration of the halogens?

26. Chemistry SOL Review—Atomic Structure Valence electron configuration and the periodic table What is the valence configuration of the halogens? ns 2 np 5 .

27. Periodic Trends in Atomic Radius, Ionization Energy, and Electronegativity. Chemistry SOL Review—Atomic Structure Atomic Radius: the radius of an atom in picometers First Ionization Energy: The energy needed to remove the first valence electron from a gaseous atom. Electronegativity: The tendency of an atom to attract electrons to itself when chemically combined with another element.

28. Periodic Trends in Atomic Radius, Ionization Energy, and Electronegativity. Chemistry SOL Review—Atomic Structure Atomic Radius : the radius of an atom in picometers 2 13 14 15 16 17 18

29. Periodic Trends in Atomic Radius, Ionization Energy, and Electronegativity. Chemistry SOL Review—Atomic Structure First Ionization Energy : The energy needed to remove the first valence electron from a gaseous atom. Ionization energy increases as you move to higher number groups. Group 18 has the highest 1 st ionization energy. Ionization energy decreases as you move down the periodic table.

30. Periodic Trends in Atomic Radius, Ionization Energy, and Electronegativity. Chemistry SOL Review—Atomic Structure First Ionization Energy : The energy needed to remove the first valence electron from a gaseous atom.

31. Periodic Trends in Atomic Radius, Ionization Energy, and Electronegativity. Chemistry SOL Review—Atomic Structure Electronegativity: The tendency of an atom to attract electrons to itself when chemically combined with another element. The halogen group has the highest electronegativity of the families. The first period has the highest electronegativity. Noble gases do not have electronegativity as the valence shell is already full.

32. Chemistry SOL Review—Atomic Structure Anions, Cations, and Electron Configuration Cations form by losing valance electrons to take on a noble gas configuration (ns 2 np 6 )

33. Chemistry SOL Review—Atomic Structure Anions, Cations, and Electron Configuration Cations form by losing valance electrons to take on a noble gas configuration (ns 2 np 6 ) So Li loses the 2s 1 electron to form Li +1 . Mg loses both 3s 2 electrons to form Mg +2 Al loses three electrons from 3s 2 3p 1 to form Al +3

34. Chemistry SOL Review—Atomic Structure Anions, Cations, and Electron Configuration Anions form by gaining valance electrons to take on a noble gas configuration (ns 2 np 6 ) So F becomes F 1- by gaining a 2p electron to have the new valance configuration 2s 2 2p 6 . S becomes S 2- by gaining two 2p electrons to have the new valance configuration 3s 2 3p 6 . N becomes N 3- by gaining three 2p electrons to have the new valance configuration 2s 2 2p 6 .

35. Isotopes: elements with the same number of protons, but a different number of neutrons. Chemistry SOL Review—Atomic Structure Carbon-14 has ___ protons and ___ neutrons 12 6 C 13 6 C 14 6 C

36. Isotopes: elements with the same number of protons, but a different number of neutrons. Chemistry SOL Review—Atomic Structure Carbon-14 has 6 protons and 8 neutrons 12 6 C 13 6 C 14 6 C

37. Isotopes: elements with the same number of protons, but a different number of neutrons. Chemistry SOL Review—Atomic Structure You figure out the average atomic mass of a compound by using a weighted average of the mass number for each isotope. Example: a sample contains 10% C-13, 60% C-12 and 40% C-14. The average atomic mass is (0.10 x 13) + (0.60 x 12) + (0.30 x 14) = 12.7 12 6 C 13 6 C 14 6 C

38. Development of the Atomic Model Thompson Model Rutherford Gold Foil Experiment and Model Bohr Model Quantum-Mechanical Model From Mark Rosengarten’s New York Regent’s Powerpoint Chemistry SOL Review—Atomic Structure

39. Thompson Model The atom is a positively charged diffuse mass with negatively charged electrons stuck in it. From Mark Rosengarten’s New York Regent’s Powerpoint Chemistry SOL Review—Atomic Structure

40. Rutherford Model The atom is made of a small, dense, positively charged nucleus with electrons at a distance, the vast majority of the volume of the atom is empty space. Alpha particles shot at a thin sheet of gold foil: most go through (empty space). Some deflect or bounce off (small + charged nucleus). From Mark Rosengarten’s New York Regent’s Powerpoint Chemistry SOL Review—Atomic Structure

41. Bohr Model Electrons orbit around the nucleus in energy levels (shells). Atomic bright-line spectra was the clue. From Mark Rosengarten’s New York Regent’s Powerpoint Chemistry SOL Review—Atomic Structure

42. Quantum-Mechanical Model Electron energy levels are wave functions. Electrons are found in orbitals, regions of space where an electron is most likely to be found. You can’t know both where the electron is and where it is going at the same time. Electrons buzz around the nucleus like gnats buzzing around your head. From Mark Rosengarten’s New York Regent’s Powerpoint Chemistry SOL Review—Atomic Structure

43. Chemistry SOL Review—Atomic Structure References www.markrosengarten.com NY Regent’s Exam Powerpoint