Trends in the Periodic Table of Elements

1. Trends in the Periodic Table of Elements

3. Atomic Radius Based on the graph, what do you think Atomic Radius means?

4. Atomic Radius Atomic Radius – size of an atom

5. Atomic Radius It ________________ as you go down a column because: increases Electrons are added to a new energy level

6. Atomic Radius It ________________ as you go across a row because: decreases Within an energy level, as you add more protons (and electrons), the heavy protons pull the light electrons in closer

7. Atomic Radius The corner of the Periodic Table with the highest atomic radius is And the corner with the lowest atomic radius is Lower left corner Upper right corner

8. Before we Move on… Atoms of all elements want to be stable They will gain or lose electrons until their outer energy level is full (like the noble gases, column 18)

9. Ionization Energy Ionization Energy – the amount of energy it takes to remove an electron

10. Ionization Energy It ________________ as you go down a column because: decreases The more total electrons an element has, the less it cares about whether or not it loses one electron

11. Ionization Energy It ________________ as you go across a row because: increases The more valence electrons an element has, the more it wants to keep its electrons

12. Ionization Energy The corner with the highest ionization energy is The corner with the lowestionziation energy is Upper right corner Lower Left corner

13. Ionization Energy Example) Which of the following elements has the highest ionization energy: sodium, argon, cesium, or radon? Argon

14. Atomic Number Electronegativity Electronegativity Electronegativity– how much an atom attracts electrons

15. Electronegativity It ________________ as you go down a column because: decreases The more total electrons an element has, the less it cares about whether or not it gets another electron

16. Electronegativity It ________________ as you go across a row because: increases The more valence electrons an atom has, the more it really wants another one to get closer to a full shell (column 18)

17. Electronegativity The corner with the highestelectronegativity is The corner with the lowestelectronegativity is Upper right (except noble gases) Lower left

18. Electronegativity Example) Which of the following elements has the highestelectronegativity: sodium, chlorine, rubidium, or iodine? Chlorine

19. Electronegativity Example) Place the following elements in order in terms of increasing (smallest to largest) electronegativity: silicon, sodium, chlorine. Sodium, Silicon, Chlorine

20. Electronegativity Example) Place the following elements in order in terms of increasing (smallest to largest) electronegativity: lithium, sodium, cesium. Cesium, sodium, lithium