1st Ionization EnergyThe amount of energy required to remove an

electron from an atom.Trend:

Increases left to right across a row.Increases bottom to top of a column.

Ex: Which of the following elements has the highest 1st ionization energy? Na, Al, Cl, or Mg?

Ex: Which of the following elements has the highest 1st ionization energy? K, Rb, H, or Li?

ElectronegativityThe force with which a nucleus is attracted to

its electronsHow strongly an atom holds on to its electrons

TrendIncreases left to right across a rowIncreases bottom to top of a column.

Ex: Which of the following elements has the highest electronegativity? Na, Al, Cl, or Mg?

Ex: Which of the following elements has the highest electronegativity? K, Rb, H, or Li?

Atomic and ionic radiusThe size of an atom or ion (we’ll talk about

ions later)Trend

Increases right to left of a rowIncreases top to bottom of a column.

Ex: Which of the following elements has the largest atomic radius? Na, Al, Cl, or Mg?

Ex: Which of the following elements has the largest atomic radius? K, Rb, H, or Li?

PracticeWhat is the name of column 1 on the periodic

table?What is the name of column 17 on the

periodic table?How many valence electrons do the noble

gases have?Draw the lewis dot diagram for arsenic.