The Periodic Table

Topic 5

Click for song

Searching For an Organizing Principle

Chlorine, bromine, and iodine have very similar chemical properties.

Mendeleev’s Periodic Table

Mendeleev’s Periodic Table (1869) How did Mendeleev organize his

periodic table? The Abbreviated History of the Periodic

Table for Regents Chemistry

6.1

Click on pix for history

A. Dmitri Mendeleev (1869, Russian)

Organized elements by

increasing ATOMIC MASS.

Elements with similar chemical properties were grouped together.

There were some discrepancies.

I. HISTORY

B. Henry Moseley

ORGANIZED ELEMENTS BY INCREASING ATOMIC NUMBER.

Resolved discrepancies in Mendeleev’s arrangement.

The Periodic Law

In the modern periodic table, elements are arranged in order of increasing atomic number.

6.1

When elements are arranged in order of INCREASING ATOMIC #, elements with similar chemical properties appear at regular intervals.

0

50

100

150

200

250

0 5 10 15 20Atomic Number

Ato

mic

Rad

ius

(pm

)

The Periodic Law

The periodic law: When elements are arranged in order of increasing atomic number, there is a periodic repetition of their physical and chemical properties.

• The properties of the elements within a period change as you move across a period from left to right.

• The pattern of properties within a period repeats as you move from one period to the next.

6.1

Periodic Table of the Elements Intro

Click on for intro

1. Horizontal rowsCalled PERIODSAll elements in the same period have the same number of ENERGY LEVELS in their atomic structure

A. Arrangement of Table

II. ORGANIZATION OF THE ELEMENTS

Click

on for

intro

2. Vertical Columns

a) Called GROUPS OR FAMILIESb) All elements in the same group have the

same number of VALENCE ELECTRONS, therefore lose or gain the SAME number of electrons, form similar CHEMICAL FORMULAS and have similar CHEMICAL PROPERTIES

ex. XCl2 Group 2:

Be +2 Cl -1 = BeCl 2

Mg +2 Cl -1 = MgCl2

Remember: When

writing formulas,

use the criss-cross

rule to cancel out

oxidation states

III. Comparing Metals, Nonmetals & Metalloids

Elements on the Periodic Table are divided into three subgroups called METALS, NONMETALS and METALLOIDS

(semimetals).

Decrease metallic propertiesDecrease metallic properties

Increase Increase

metallic metallic

propertiesproperties

Increase Increase

nonmetallic nonmetallic

propertiesproperties

METALS: located on the LEFT SIDE of the periodic table (except H); MORE THAN 2/3 of all elements

1. Chemical properties tend to LOSE ELECTRONS EASILY have LOW IONIZATION ENERGY (energy

needed to remove electrons) Metallic character INCREASES as

ionization energy decreases. have LOW ELECTRON AFFINITY

(attraction for electrons) form POSITIVE IONS when combining

with other atoms FRANCIUM most reactive metal: See

Table J http://castlelearning.com/review/reference/chem%20table%20j.htm

2. Metals Physical Properties

good conductors of heat and electricity

LUSTROUS - reflect light, shine when they are polished

MALLEABLE - can be rolled or hammered into sheets

DUCTILE - can be drawn into wires

are SOLIDS at room temperature except for MERCURY (liquid)

B. NONMETALS

1. Chemical properties tend to GAIN electrons to form

NEGATIVE IONS have high electron affinities

(electronegativity) produce COVALENT bonds by

SHARING electrons with other nonmetals

FLUORINE most reactive nonmetal: see Table J

located on the right side of

the periodic table

2. Nonmetals Physical Properties

exist as gases, molecular solids, or network solids at room temperature except BROMINE (liquid)

BRITTLE - (shatters when struck) DULL - does not reflect light even when

polished POOR CONDUCTORS of heat and

electricity Allotropes: Different SHAPE & PROPERTIES

forms from the same element.CARBON: coal; diamond, graphite OXYGEN: O2; O3 (OZONE)

C. METALLOIDS

Found lying on the jagged line between metals and nonmetals flatly touching the line (except Al and Po).

B,Si,Ge,As, Sb, & Te Exhibit properties of both

metals and nonmetals Behave as nonmetals but

their conductivity is like metals

SEMICONDUCTORS – Si and Ge

A. Periodic LawWhen elements are arranged in order of

increasing atomic #, elements with similar properties appear at regular intervals.

0

50

100

150

200

250

0 5 10 15 20Atomic Number

Ato

mic

Ra

diu

s (

pm

)

IV. Periodic Trends

http://castlelearning.com/review/reference/chem%20table%20s.htm

1) Ionization Energy

Energy needed to remove the most loosely bound electron from a neutral gaseous atom

X + energy X+ + e-

Trends in Ionization Energy

6.3

Trends in Ionization Energy

IE increases as you move across a periodWhy?The nuclear charge (atomic #) is

increasing therefore greater attraction of the nucleus for electrons hence harder to remove an electron

Trends in Ionization Energy

IE decreases as you move down a groupWhy?

Atom size increases making the outermost electron farther away from the nucleus therefore making it easier to remove

Shielding increases

Why opposite of atomic radius?

In small atoms, e- are close to the nucleus where the attraction is stronger

Why small jumps within each group?

Stable e- configurations don’t want to

lose e-

Ionization Energy cont.

1

2

3

4 5

6

7

First Ionization Energy

Increases UP and to the RIGHT

3. Ionization Energy – Table S

Click on for video

clip

Successive Ionization Energies

Mg 1st I.E. 736 kJ

2nd I.E. 1,445 kJ

Core e- 3rd I.E. 7,730 kJ

Large jump in I.E. occurs when a CORE e- is removed.

Ionization Energy cont.

1

2

3

4 5

6

7

Increases DOWN Decreases Across

½ the distance between nuclei © 1998 LOGAL

2. Atomic Radius – Table

S

Click on for video

clip

Why is it smaller to the right?

Increased nuclear charge(# p+) without additional shielding pulls e- in tighter

Why is it larger going down?

Higher energy levels have larger orbitals

Shielding - core e- block the attraction between the nucleus and the valence e-

Atomic Radius cont.

Electronegativity- ability for an atom to attract electronsBased on a scale of 4, Fluorine having the greatest

electron affinity

A. Metals lose e-

Form Cations (+)

get smaller

© 2002 Prentice-Hall, Inc.

B. Nonmetalsgain e-

Form Anions (–)

Get larger

3. Electronegativity – Table 3. Electronegativity – Table SS

Click on for video clip

Trends in Electronegativity

Representative Elements in Groups 1A through 7A

6.3

1

2

3

4 5

6

7

Melting/Boiling PointHighest in the middle of a period.

4. Melting/Boiling Point – Table S

Periodic Trends Summary(use reference Table S for data comparison)

TrendAcross a Across a period period

Up a groupUp a group

Ionization energy

increasesincreases increasesincreases

Electronegativity

increasesincreases increasesincreases

Atomic radii decreasesdecreases decreasesdecreases

Metallic properties

decreasesdecreases decreasesdecreases

Click on for video clip

IV. Classification

Alkali MetalsAlkaline Earth MetalsTransition MetalsHalogensNoble Gases

Click for

song

Group 1: Alkali Metals

extremely reactive (not found free in nature)

form stable ionic compoundsreact with water to form a basereact with air to form oxidesreact with acids to form salts

Click on for video clip

Group 2: Alkaline Earth Metals

reactive (not found free in nature) - form stable ionic compounds

react with water to form a basereact with air to form oxides react with acids to form salts

Click on for video clip

Groups 3-11: Transition Metals

multiple positive oxidation statesLose electrons from two outermost

energy levelsIons form colored solutions

Group 15 – unique features

Members range from typical nonmetals (nitrogen and phosphorus) through metalloids (arsenic and antimony) to metals (bismuth)

NitrogenForms stable diatomic molecules with a triple

bondComponent of proteinForms some unstable compounds that are used as

explosives

PhosphorusComponent of nucleic acids (DNA, RNA)More reactive than nitrogen at room temperature

Group 16 – unique Features

Members range from typical nonmetals (oxygen and sulfur) through metalloids (selenium and tellurium) to metals (polonium)

Solids except oxygen Oxygen can exist as O2 and O3 (it is an allotrope)

Polonium is radioactive

Group 17: Halogens

very reactive nonmetals - high electronegativity

not found free in natureform diatomic molecules when

freereact with metals to form salts

(halides)Found in all three phases (s, l,

g) due to differences in Van der Waals forces (these are weak)

Group 18: Noble Gases

Have complete outer shellsAlmost inert (not reactive);

stableKrypton, xenon, and radon

form compounds with oxygen and fluorine

Referred to as monatomic gases

TODAY……..TODAY……..

1. 1. Assemble into your groups according to Take your notes and 5 questions with you. Using your notes, discuss & complete the Teachback WS questions pertaining to your group. Use the post-it notes for any

questions you may have THAT MAY NEED ANSWERING

3. BEGIN your teachback, this NOT a silent lesson – use your low voices to teach the other members. Ask your questions to ascertain clarity. At the end of this session, everyone in the group should have the Teachback WS completed.

Use the post-it notes for any questions you may have THAT NEED ANSWERING..

Once finished, begin RB questions 46-90.

Cooperation and diligence is necessary….. I will be watching and listening.

TEACHBACK PROJECT REVIEW

Alkali MetalsAlkaline Earth MetalsTransition MetalsHalogensNoble Gases

Click for

song

GROUP 1

1. The name of this group is ALKALI METALS

2. Does this group contain metals or nonmetals? METALS

3. Alkali metals (lose or gain)l LOSE electrons becoming (positive or negative) ions? POSITIVE

4. What happens to the reactivity of the elements in this group as the atomic number increases. (increases or decreases) INCREASES

4. Are they (more or less) MORE reactive than all of the elements in Group 2 and why? THEY HAVE LOW IONIZATION ENERGIES

Group 1 continued:

5. Can these compounds be found in nature in the elemental or combined state? COMBINED STATE IN THE FORM OF A SALT

6. What type of compounds do they normally form (ionic or covalent)? IONIC (M + NM)

7. If element Y represents an alkali metal, what is it’s general formula for the reaction with a:

Chloride: YCl Oxide: Y2O

8. What is the most reactive metal in this group? FRANCIUM OR CESIUM

GROUP 21. The name of this group is ALKALINE

EARTH METALS.

2. Does this group contain metals or nonmetals? METALS

3. They (lose or gain) LOSE electrons & form (positive or negative) ions POSITIVE ?

4. Describe the reactivity of the elements in this group as the atomic number increases (increases or decreases) INCREASES

5. Are they (more or less) LESS reactive than all of the elements in Group 1 and why? _________________________________________

Group 2 continued:

5. Can these compounds be found in nature in the elemental or combined state? COMBINED STATE IN THE FORM OF A SALT

6. What type of compounds do they normally form (ionic or covalent)? IONIC (M + NM)

7. If element Z represents an alkaline earth metal, what is it’s general formula for the reaction with a:

Chloride ZCl2 Oxide: ZO

GROUP 151. What is this group referred to as? NITROGEN GROUP

2. Name the diatomic element in this group? NITROGEN

3. Classify each element in this group as a metal, non-metal or semi-metal (metalloid).

metals: BISMUTH nonmetals: NITROGEN, PHOSPHORUS semi-metal: ARSENIC. ANTIMONY

4. What happens to the reactivity of a non-metal as the atomic number increases (increases or decrease) DECREASES .

5. Which is the most reactive non-metal in this group? PHOSPHORUS

6. Is nitrogen a (diatomic or monatomic) DIATOMIC molecule & what type of bond is found in nitrogen? TRIPLE COVALENT

GROUP 161. Classify each element in this group as a metal, non-metal

or semi-metal.metals: POLONIUM nonmetals: OXYGEN, SULFUR, SELENIUM semi-metal: TELLERIUM

2. Name the diatomic element in this group. OXYGEN

3. Define an allotrope? DIFFERENT FORMS OF AN ELEMENT IN THE SAME PHASE WITH HAVING DIFF CHEM & PHYSICAL PROPERTIES

4. Which element(s) in this group is an allotrope? PHOSPHORUS, SULFUR, OXYGEN (O2, O3)

5. What type of element is Polonium? RADIOACTIVE METAL

TRANSITION ELEMENTS (groups 3B-

12)1.1. Which element is a liquid at room temperature? Which element is a liquid at room temperature?

MERCURY (Hg)

2. What are the four main characteristic chemical 2. What are the four main characteristic chemical properties of transition elements? properties of transition elements?

MULTIPLE POSITIVE OXIDATION STATES IONS FORM COLORED SOLUTIONS LOSE ELECTRONS FROM TWO

OUTERMOST ENERGY LEVELS UNFILLED D ORBITALS

GROUP 17

1. The name of this group is HALOGENS

2. Classify the elements in this group: NONMETALS

3. Halogens (lose or gain) GAIN electrons becoming (positive or negative) ions? NEGATIVE

4. Why is astatine not included much in these discussions? NOT ENOUGH AVAILABLE TO STUDY

5. What would the general formula of a Group 17 element (represented by X) combined with magnesium of

group 2? MgX2

Group 17 continued:

6. What is the most reactive element in this group? FLUORINE

7. Can these compounds be found in nature in the elemental or combined state? COMBINED STATE AS SALTS

8. What type of salts do these elements form? HALIDES

9. For each state of matter, list the element(s) in this group. solid: IODINE liquid: BROMINE gas: CHLORINE, FLUORINE

10. What type of forces of attractions account for the different states of matter that exist and the high MP’s and BP’s as you go down the group? VAN DER WAALS FORCES

(weak forces that get stronger as you go down the group )

GROUP 18The name of this group is called NOBLE GASES.

What type of molecules do these gases form? (monatomic or diatomic) MONATOMIC

Describe the electron arrangement in the outermost energy level of all these elements. STABLE OCTECT – INERT GAS STRUCTURE

Which element has only two electrons? HELIUM

Describe the reactivity of the elements in this group. THEY ARE UNREACTIVE (Kr and Xe can be forced to react with F in lab settings)