2. How are the elements organized in the modern periodic table?

3. Look at the rows and columns of each chart. Describe the purpose to your neighbor.

4. Science Standard 8.7.a: Students know how to identify regions corresponding to metals, nonmetals, and inert gases.

5. atomic mass: the average mass of all the isotopes of an element. periodic table: an arrangement of elements showing the repeating pattern of their properties. period: horizontal rows on P.T. group: vertical columns on P.T. chemical symbol: representation of an element usually consisting of 1 or 2 letters.

6. Mendeleev’s Periodic Table Mendeleev discovered the pattern that led to the periodic table. In 1869, a total of 63 elements had been discovered. A Russian scientist, Dmitri Mendeleev noticed that a pattern of properties appeared when he arranged the elements in order of increasing atomic mass.

7. The Modern Periodic Table The properties of an element can be predicted from its location on the periodic table. The modern periodic table contains more than 100 elements. The elements are arranged in order of increasing atomic number.

8. The Modern Periodic Table There are 7 periods, or horizontal rows in the P.T. A period contains a series of different elements. From left to right, the properties of the elements change in a pattern. Metals are shown on the left of the table, with the most reactive metals on the far left. Nonmetals are located on the right, with the most reactive next to the inert gases on the far right. Semimetals are found between metals and nonmetals.

9. The Modern Periodic Table Groups are the vertical columns of the periodic table. A group, or family, consists of elements with similar characteristics. Group 1 elements react violently with water. Group 2 elements react with water slowly or not at all. Group 17 elements react violently with Group 1 elements. Group 18 elements rarely react at all.

10. Elements are organized into rows and columns based on their atomic number.

13. Each square in the periodic table lists four pieces of information: an element’s atomic number, chemical symbol, name, and atomic mass.

14. How many periods does the periodic table contain? Seven (7) In what order did Mendeleev arrange the elements in his periodic table. increasing atomic mass

15. Answer #1-4 Finish the worksheet. Complete the extension.

16. EXTENSION  Write a detailed SUMMARY of the section and complete the UNANSWERED QUESTIONS section of your notes.  Choose two of the remaining Depth & Complexity ICONS in your notes and explain how they relate to this section.  Finish the Development of Atomic Theory Timeline Booklet.