Vocabulary Week 10 Metalloids Alkali Metals Alkaline Earth Metals Halogens Noble Gases affable gossamer flout axiomatic Only 9 words this week

Review for Quiz 6.3 Location & Characteristics of: –Metals –Non-metals –Metalloids Representative Elements Transition Elements Family names & locations Periods Valence electrons Quiz on Thursday!

Definition of periodic Marked by repeated cycles Happening at regular intervals Example of the word periodic: –Periodically –Periodicals –Periodic Table of Elements

Periodic Trends Atomic Radius –half of the distance between adjacent nuclei in a crystal of the element Trend –Within a period (row): DECREASES Why? –More positive pull on electrons the same distance away Linucleus1s 2 s2 1 Bnucleus1s 2 2s 2 2p 1

Periodic Trends Atomic Radius = half of the distance between adjacent nuclei in a crystal of the element Trend –Within a group (column): INCREASES Why? –Increasing number of energy levels Linucleus1s 2 s2 1 Nanucleus1s 2 2s 2 2p 6 3s 1 Knucleus1s 2 2s 2 2p 6 3s 2 3p 6 4s 1 Rbnucleus1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 6 5s 1

Periodic Trends Atomic Radius Trend –Within a period (row): DECREASES –Within a group (column): INCREASES

Which has the largest atomic radius? Magnesium (Mg) or Sulfur (S)? Magnesium (Mg) or Barium (Ba)?

Which element is smaller? a.Nitrogen b.Oxygen

Which element is bigger? a.Potassium b.Flourine

Ionic Radius = the distance from the nucleus to the outer edge of an atom with a charge Ion = –an atom with a positive or negative charge –Valence electrons can be either gained or lost Lose electron = lose negative charge  positive Gain electron = gain negative charge  negative

To determine the charge of ion: Charge = protons – electrons AtomProtonsElectronsChargeIdentity

Trend –Within a period (row): Left side (wants to lose electrons to get to 8): smaller positive ions –Why? When we lose electrons… »May lose of energy level »Less repulsion between electrons (electrostatic repulsion) Right side (wants to gain electrons to get to 8): larger negative ions –Why? When we gain electrons »More repulsion between electrons (electrostatic repulsion)

Ionic Radius Trend –Within a group (column): Increase Why? –More energy levels!

Which element has the larger ionic radius? a.Calcium b.Oxygen

Periodic Trends Ionization Energy = –energy required to remove an electron –Think how strong does the nucleus hold it’s valence electrons? Strong hold = High energy

Octet Rule –All atoms will gain or lose electrons in order to acquire a full set of eight (two) valence electrons

Ionization Energy = how strong is the nucleus’s hold on valence electrons –Within a period (row): INCREASES Atoms get smaller as you go across—this makes it easier to hold electrons –Within a group (column): DECREASES Atoms get bigger as you go down—this makes it harder to hold electrons Lots of energy Little energy

Which element has the higher ionization energy? a.Nitrogen b.Oxygen

Which element has the lower ionization energy? a.Magnesium b.Cesium

Periodic Trends Electronegativity = ability to attract electrons Flourine (F) is the most electronegative element Trend –Within a period (row): INCREASES –Within a group (column): DECREASES F

Which element is more electronegative? a.Potassium b.Bromine

Which element is smaller? a.Sodium b.Lithium

Which element has the higher ionization energy? a.Cesium b.Oxygen