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 electronsQuiz 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

Li nucleus 1s2s21

B nucleus 1s22s22p1

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

Li nucleus 1s2s21

Na nucleus 1s22s22p63s1

K nucleus 1s22s22p63s23p64s1

Rb nucleus 1s22s22p63s23p64s23d104p65s1

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

Atom Protons Electrons Charge Identity

1 11 10

2 17 18

3 3 2

• 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