I. History of the P.T. A.) Dmitri Mendeleev –Russian Chemist who 1st arranged elements in usable...

I. History of the P.T.

• A.) Dmitri Mendeleev

– Russian Chemist who 1st arranged elements in usable manner (1869).

– Arranged elements in order of increasing atomic mass (“weight”).

History - Mendeleev (cont’d)

• Noticed chemical and physical properties appearing at periodic intervals.

• Paved the way for current P.T.

• “Father of the Periodic Table”

• Mendeleev link (pictures 1)

History – Henry Moseley

B.) Henry Moseley (1915)

• “Reorganized” the P.T.

• Arranged according to increasing atomic #.

• Current (present) P.T.

History – Periodic Law

• Periodic Law - Relationship b/t properties of elements and their atomic #.

• Physical and Chemical properties show a periodic pattern when arranged according to atomic #.

• P.T. is arranged according to this law.

II. Division of the P.T.

• Q.: How is the electron configuration affected???

– P.T. showing Ionization

A.) General Info.

• P.T. often includes phase at room temperature (temp.)

“STP” (Standard Temperature and Pressure) • Table A on Chemistry Ref. Tables.

• 3 Phases of matter . . .

– Solid (s), liquid (l), gas (g)

Phases @ STP

• Solid(s) – Vast majority of elements

• Liquid(l) – Hg (mercury – metal),

Br (bromine – nonmetal).

• Gas(g)– H, O, F, N, Cl, + Group 18

Group 18 = He, Ne, Ar, Kr, Xe, Rn

B.) Periods

• Horizontal () rows (1-7)

• Period # = # of E.L. (a.k.a. “principal energy levels” or “shells”)

– Eg.1: Elements in Period 3 have _____E.L.

Periods (cont’d)

Na Mg Al Si P S Cl Ar

• Q.1.: List how many E.L. each element has?

• Q.2.: List how many valence electrons each element has?

Periods (cont’d)

• # of valence electrons increases from left right

Periods (cont’d)

• Q.3.: How can we describe the location of solids and gases within a period?

• Solid (left side) Gas (right side)

• Q.4.: How can we describe the location of Metals and Nonmetals within a period?

• Metals (left side) Nonmetals (right side)

C.) Groups

• Vertical (up and down) columns (1-18).

1.) Elements in same group = same # valence electrons

– Except Helium.

Quick Review

• Q.1: What are valence electrons?

• Q.2: What is the maximum # of valence electrons allowed in an atom?

• Q.3: How many electrons do all elements want to have?

Groups (cont’d)

• Elements in the same group have more in common than elements in the same period.

• The closer the elements in the same group, the more similar their properties.

Important Group Names

Group(s) Group Name

1 Alkali Metals (Very Reactive)

2 Alkaline Earth Metals (Very Reactive)

3-11 Transition Metals (Transition Elements)

17 Halogens (Very Reactive)

18 Noble Gases (Not Reactive)*Stable

Properties of the Elements

• Q. What are the 3 types (not phases) of elements?

– Draw the Periodic Table and divide it according to these 3 types of elements.

METALS

• 75% of the Periodic Table

METALLOIDS (Semi-Metals)

• Stair line on P.T. (label it!)

• Share both Metal / Nonmetal properties

• Metalloids = B, Si, As, Ge, Sb, Te, At

– Al and Po are NOT metalloids.

• What are they???

NONMETALS

• Contain the only elements on the P.T. in the gas (g) phase.

Properties of the Elements

METALS NONMETALS

• Draw the Bohr models of Sodium and Chlorine (side-by-side)

– Q. How do the structures of these elements differ?

– Q. Describe what each will do to achieve the Octet Rule.

– P.T. showing Ionization

Properties of Metals

• Solid (except Hg)• Silver-colored (except Cu and Au)• Soft• Malleable – “hammered into shape”• Ductile – form into wire• Excellent conductors of heat and electricity• High melting point (M.P.)• Luster – shiny• Transitional Metals form colored compounds• Few valence electrons• Lose electrons to form “+” ions

• ** Which of the following metal ions forms a colored compound when bonded to a nonmetal?

1. K+1

2. Ba+2

3. Cu+2

4. Sr+2

Properties of Nonmetals

• All Phases (solid, liquid (Br), and gas)• Dull surface (no luster)• Hard solids• Brittle (not malleable or ductile)• Poor conductors of heat and electricity.• 4 or more valence electrons• Gain electrons to become “–” ions• Low Melting Point (in general)

Properties of Metalloids

• All solid (s) @ STP

• Contain properties of both Metals and Nonmetals.

• (First) Ionization Energy – amount of energy needed to remove the most loosely held electrons.

• Draw the Bohr models of Sodium and Fluorine (side-by-side)

– Q.1. Which element has a greater ionization energy?

– Q.2. What can we conclude about the ionization energy of metals compared to nonmetals?

The “Shielding” Effect

• The “Shielding” Effect refers to the weakening of attraction (“magnetic pull”) between the nucleus and the valence electrons, caused by the energy levels (shells) in between them.

** Shielding LOWERS the Ionization Energy! **

– Q.1. When does “Shielding” increase?

– Q.2. Which element would have more shielding, Chlorine or Bromine?

(First) Ionization Energy

• Draw Lithium and Sodium side-by-side

– Q.1. Which element has a greater ionization energy?

** Think in terms of MAGNETS! ** . . . (and the Shielding Effect)

• Q.4: Draw Na, Mg, and K side by side. Which of these 3 examples will take the least amount of energy (“ionization energy”) to lose 1 e ??? Why?

• Q. Which Metals do you think contain the MOST metal properties??? Explain.

• Q. Which Nonmetals do you think contain the MOST nonmetal properties??? Explain.

• Electronegativity – the attraction for electrons by an element

“Electronegativity is the attraction for an e”

• Draw the Bohr models of Lithium and Fluorine (side-by-side)

– Q.1. Which element has a greater electronegativity?

– Q.2. What can we conclude about the electronegativity of metals compared to nonmetals?

Electronegativity

• Draw Fluorine and Chlorine side-by-side

– Q.1. Which element has a greater electronegativity?

** Think in terms of MAGNETS! **

Electronegativity

• Draw Neon

– Q.1. How would you describe the electronegativity?

** Think in terms of MAGNETS! **

Atomic Radius

• Atomic Radius:• ½ the distance between two adjacent nuclei.

Trends in the P.T.• 1.) Reactive Groups:

– Metals: Group 1 (Alkali) and Group 2 (Alkaline Earth) are VERY REACTIVE!

• Group 1 are the MOST REACTIVE Metals.

• Reactivity of Group 1

– Nonmetals: Group 17 (Halogens) are VERY REACTIVE!

– Group 18 is STABLE (NOT Reactive)

Trends in the P.T.

• Atomic Radius– Within a Period

– Within a Group

• (Atomic Radii) (Atomic Radii.2) (Atomic Radii.3)

Trends in the P.T.

• Ionization energy

– Within a Period:

– Within a Group:

Trends in the P.T.

• Electronegativity

– Within a Period:

– Within a Group:

Graphing Trends

• Rule #1: Always set up graph as you do in all science/math classes.A.) Title: Independent (X) vs. Dependent (Y) Variable

B.) Set up X (independent) and Y (dependent) axes.

C.) Always have Equal INCREMENTS!!!

D.) Use as much of the graphing space as possible.E.) Always write a CONCLUSION!!!

• Rule #2: Make a Table!

– Refer to this table when making the graph.

Rule #3: Always circle your dots!

Graphing (Cont’d)

• 1.) Graph Group 1 (atomic #) vs. Electronegativity (Electron Affinity)

• 2.) Graph the trend of Ionization Energy in Period 2. (Period 2 vs. Ionization Energy)

• 3.) Graph the trend of Atomic Radius in Group 1. (Group 1 vs. Atomic Radius)

• Graphing Classwork/Homework.

Ionic Radius

• Ionic radius – The new radius of an element, after it becomes an ion.

– Eg. Draw Na and Cl. Show their radius as ions.

• What is the general rule for the ionic radius of Metals? Nonmetals?

Allotropes

• Allotrope: An element that exists as 2 or more forms in the same phase. Oxygen Ozone

FormO2 O3

Phase(g) (g)

The Element Song

The Element Song