1. Electron Configuration & Periodic Table

2. Periods & Blocks of Periodic Table Period NumberNumber of elements in period Sublevels in order of filling 121s 282s 2p 383s 3p 4184s 3d 4p 5185s 4d 5p 6326s 4f 5d 6p 7327s 5f 6d 7p

4. Without looking at the periodic table, give the group, period, and block in which the element with the electron configuration [Rn]7s 1 is located.

5. Group 1, seventh period, s Block

6. Without looking at the periodic table, give the group, period, and block in which the element with the electron configuration [He]2s 2 is located.

7. Group 2, second period, s Block

8. How does the reactivity of the element [He]2s 2 compare with the reactivity of the element [He]2s 1 ?

9. Both are in the same period, but element [He]2s 2 is in Group 2 and the element [He]2s 1 is in Group 1. Therefore, the element [He]2s 1 is more reactive.

10. Relationships among Group Numbers, Blocks, and Electron Configuration Group NumberGroup Configuration BlockComments 1, 2ns 1,2 sOne or two electrons in ns sublevel. 3-12(n-1)d 1-10 ns 0-2 dSum of electrons in ns and (n-1)d levels equals group number. 13-18ns 2 np 1-6 pNumber of electrons in np sublevel equals group number minus 12.

11. Without referring to the periodic table, write the outer electron configuration for the Group 16 element in the third period. Then name the element and characterize it as a metal, nonmetal, or metalloid.

12. 3s 2 3p 4 ; s, nonmetal

13. For each of the following electron configurations, locate the corresponding element in the periodic table by determining its Block, Period, and Group. Then use the periodic table to name the element and predict whether it is likely to be of high or low reactivity. A. [He]2s 2 2p 3 B. [Xe]4f 14 5d 10 6s 1 C. [Rn]7s 1 D. [Ar]3d 10 4s 2 4p 5

14. A. p Block, second period, Group 15, Nitrogen, low reactivity. B. d Block, sixth period, Group 11, Gold, low reactivity. C. s Block, seventh period, Group 1, Francium, high reactivity. D. p Block, fourth period, Group 17, Bromine, high reactivity.