Atomic Size

Explain why Fluorine has a smaller atomic radius than oxygen.

Because they are in the same period they have the same # of energy levels. However, since Fluorine has an attracted nuclear charge, and the level is more attracted to the nucleus or, "pulled in."

Carbon or Boron

Boron

Explain why fluorine has a smaller atomic radius than chlorine.

Chlorine has more occupied energy levels than fluorine (further down on the periodic table) so, the valance shell of chlorine is farther from the nucleus. The increases in protons between fluorine and chlorine don't matter because of the outer shell.

Arrange these elements in order of decreasing atomic size: sulfur, chlorine, aluminum, and sodium. Does you arrangement demonstrate a periodic or a group trend.

Na, Al, S, Cl (periodic?)

As you move from left to right across a period on the periodic table the size of an atom will ________________________.

decreases

This happens as you move down the group each element has one more occupied ____________________________ than the last one.

energy levels

Within a period the elements will have the same number of occupied ___________________________________.

energy levels

As you move from top to bottom down a group on the periodic table the size of an atom will ______________________.

increase

Electrons which are further from the nucleus are ____________ attracted to the nucleus because of this effect.

less

Silicon or magnesium

magnesium

This happens because as you move across a period each element has one more _____________________ in its nucleus than the last one.

protons

The _______________________ effect is caused by inner electrons interfering with the attraction of outer electrons for the protons in the nucleus.

shielding

Circle the element in each of the following pairs with the greater atomic size? Sodium or lithium

sodium