Clicker #1 How many unpaired electrons does sulfur contain in its ground state? (Hint: Draw an orbital diagram.) A)0 B)1 C)2 D)3 E)6

Valence Electrons Highest or outermost energy level electrons Where the chemistry happens! Look at principal quantum level n Sulfur: 1s 2 2s 2 2p 6 3s 2 3p 4 Valence electrons are in n = 3 level Valence electrons = = 6 electrons

Atomic Radius (Size) Increases down a group Hydrogen INCREASES! Francium Orbitals are getting larger and electrons fill further and further from the nucleus at higher energy levels

Atomic Radius (Size) Decreases across a row (period) – outer electrons in the same energy level Hydrogen Fluorine DECREASES! More protons in each element as you move across the row. More protons will create a stronger positive force, thus attracting the electrons more strongly, pulling them in and shrinking the size.

Clicker #2 Which of the following elements has the largest atomic radius? A) Ca B) Al C) N D) Sr E) F

Ionization Energy Decreases down a group Hydrogen DECREASES! Francium Orbitals are getting larger and electrons fill further and further from the nucleus at higher energy levels. Electrons are not as tightly bound by the nucleus at higher energy levels so it takes less energy to remove an outer electron.

Ionization Energy Increases across a row (period) – outer electrons in the same energy level Hydrogen Fluorine INCREASES! More protons in each element as you move across the row. More protons will create a stronger positive force, thus attracting the electrons more strongly and pulling them in closer to the nucleus, requiring MORE energy to remove an outer electron.

Clicker #3 Which of the following elements has the largest ionization energy? A)P B)Al C)Cl D)Ba E)K