Period Table Trends

1. Periodic Table of Elements Chapter 6 Notes

2. Modern Periodic Table Designed by Demitri Mendeleev based on atomic mass (1869) Modified by Henry Moseley based on atomic number (1926)

3. Classifying Elements

5. Brittle

6. Most are gases at room temp

8. Malleable

9. Solid at room temp (except Hg)

10. High luster/sheenGold Bromine Gas

11. sToP & tHinK – metal or nonmetal 1. A gaseous substance that partially conducts electricity. 2. Solid that is malleable and shiny. 3. Solid that is brittle and dull color. 4. Solid that conducts electrical current and has high luster. 5. Has 7 valence electrons 6. Found on the right of the ‘staircase’ 7. Has 1 valence electron 8. d and f block elements

12. Elements in the same group have similar properties! (Periodic Law) Group 1 - Alkali Metals Group 2 - Alkaline Earth Metals d block - Transition Metals f block - Inner Transition Metals Group 7 - Halogens Group 8 - Noble Gases Reactivity increases from top to bottom for 1A, 2A Reactivity decreases from top to bottom for 7A Classifying Elements – Let’s Look at the Periodic Chart

13. State the name of the group / family for each: Magnesium Bromine Argon Has 8 valence electrons Group 1A Copper Tend to lose one electron to be more stable (remember octet rule). sToP & tHinK

14. A groups - representative elements (s and p blocks, except noble gases) Display varied properties by column B groups - transition elements & inner transition elements (d and f blocks) Fairly similar properties A Groups & B Groups

15. Atomic Radius

16. Let’s Look @ Atomic Radius Decreases across the period (row/horizontal) Increases down the group (column/vertical) WHY?!? – 2 Reasons 1. Each added proton increases the positive nuclear charge… as electrons are added to principal energy levels the level gets smaller. 2. Electrons added to a new principal energy level are ‘shielded’ from the positive nucleus by the electrons in lower levels.

17. SToP & THinK 1. Why does atomic radius decrease as you move from left to right on the PT? 2. Why does atomic radius increase as you move down each group on the PT?

18. Anions (- charged) larger than neutral atom of the same element Anions Ionic Radius

19. CationsIonic Radius Cation(+ charged) smaller than neutral atom of the same element

20. SToP & THiNk 1. Which has a larger radius for each: K or K+? S or S2-? 2. Explain why.

21. Ionization Energy(IE)Trends The amount of energy required to remove an electron from an atom. Increases up the periodic chart and from left to right.

22. Ionization Energy(IE)Trends (IE) Increases Up the Periodic Chart. (IE) Increases from Left to Right

23. ElectronegativityTrends The ability of an atom to pull electrons in a chemical bond. Due to pull from protons and how close electrons are to nucleus. More electronegative = stronger pull on electrons Same pattern as ionization energy (IE)

25. SToP & THiNk Which is more electronegative? Ca or Cl P or O In your own words, explain why ionization energy and electronegativity follow the same trend pattern on the periodic table.