1. Atomic Radius

2. Boron (B) or Indium (In)? WHY?
Which is bigger?
Boron (B) or Indium (In)? WHY?

3. More energy levels – valence electrons are farther from nucleus
Which is bigger?
Indium (In)
More energy levels – valence electrons are farther from nucleus

4. Niobium (Nb) or Cadmium (Cd)? WHY?
Which is bigger?
Niobium (Nb) or Cadmium (Cd)? WHY?

5. Which is bigger?
Niobium (Nb) Fewer protons – valence electrons are not as attracted to the nucleus

6. Xenon (Xe) or Radon (Rn)? WHY?
Which is bigger?
Xenon (Xe) or Radon (Rn)? WHY?

7. More energy levels – valence electrons are farther from nucleus
Which is bigger?
Radon (Rn)
More energy levels – valence electrons are farther from nucleus

8. Uranium (U) or Francium (Fr)? WHY?
Which is bigger?
Uranium (U) or Francium (Fr)? WHY?

9. Fewer protons – valence electrons are not as attracted to the nucleus
Which is bigger?
Francium (Fr)
Fewer protons – valence electrons are not as attracted to the nucleus

10. As Zeff increases across a period…
What happens to atomic radius?

11. As Zeff increases across a period…
Radius decreases – effective core charge increases, so valence electrons are more attracted to the nucleus

12. As the number of shells increases down a group…
What happens to atomic radius?

13. As the number of shells increases down a group…
Radius increases – valence electrons are farther from the nucleus

14. What is the SMALLEST atom on the periodic table? WHY?

15. What is the SMALLEST atom on the periodic table?
Helium – fewest number of energy levels, greater Zeff than hydrogen