History of Periodic Table

Evaluation/ Assessment Objective Today I will be able to: Analyze how elements are arranged on the periodic table based on properties Explain the history of the periodic table. Apply the trends of ionization energy, electronegativity and atomic radius, electron affinity and ionic radius to problem solving. Evaluation/ Assessment Informal assessment – Listening to group interactions and discussions as they activity and complete practice Formal Assessment – Analyzing student responses to the exit ticket and practice Common Core Connection Build Strong Content Knowledge Value Evidence Reason abstractly and quantitatively Look for and make use of structure

Lesson Sequence Evaluate: Warm-Up Engage/Explore: Periodic Table Activity Explain: History of Periodic Table Notes Elaborate: Periodic Trends Intro Evaluate: Exit Ticket

Warm-Up Which of the following ions are not likely to form? Explain your answer based off of the trends we have discussed this unit. Al3+ Al2+ Al5-

Objective Today I will be able to: Analyze how elements are arranged on the periodic table based on properties Explain the history of the periodic table. Apply the trends of ionization energy, electronegativity and atomic radius, electron affinity and ionic radius to problem solving.

Homework STEM Fair Due Friday, November 19

Agenda Warm-Up Periodic Table Activity History of Periodic Table Notes Periodic Trends Intro Exit Ticket

Periodic Table Activity Recreating the periodic table http://www.nclark.net/MendeleevLab.htm

Periodic Table Activity Directions Work with your row to complete the activity Arrange the known elements on the cards into the order of the periodic table Place the unknown’s in their spot based on the properties of the elements Hint: you are only working with elements in the s and p block

Discussion What process did you use to arrange your unknowns on the periodic table? Did some properties help determine the unknowns more than others? Were there any exceptions?

Answers Unknown Element 1 Mg 2 F 3 Rb 4 Kr 5 S 6 Ge 7 Sb

History of the Periodic Table

Johann Dobereiner (1829) Law of Triads - in triads of elements the middle element has properties that are an average of the other two members when ordered by the atomic weight Example - halogen triad composed of chlorine, bromine, and iodine

John Newlands (1864) Law of Octaves - states that any given element will exhibit analogous behavior to the eighth element following it in the periodic table

Dmitri Mendeleev (1871) Developed the first Periodic Table He arranged his table so that elements in the same column (groups) have similar properties; increasing atomic mass

Dmitri Mendeleev (1871) Broke the trend of arranging elements solely by their atomic mass Wanted to keep elements with similar properties in the same columns Left gaps in his early tables; predicted elements that had not been discovered would fill in those gaps - Ekasilicon  Germanium - Germanium was discovered in 1886

Dmitri Mendeleev (1871)

Henry Moseley (1913) Periodic Law - when elements are arranged in order of increasing atomic number, their physical and chemical properties show a periodic (repeating) pattern The periodic law is the basis for arranging elements in the periodic table

Glenn Seaborg He reconfigured the periodic table by placing the actinide series below the lanthanide series Awarded a Nobel Prize in 1951 Element 106, Seaborgium (Sg), is named in his honor

Introduction to the Periodic Trends

Atomic Radius Distance from the center of an atom to the outermost edge of the electron cloud

Electronegativity The ability to attract electrons in a chemical bond

Ionization Energy Energy needed to remove an electron from an atom High ionization energy means atoms hold their electrons very tightly

Exit Ticket – Make a prediction Which elements do you think would have a higher ionization energy? Na or Ne Mg or Ba