The PeriodicThe Periodic

TableTable

Classification of Elements

Metals, Nonmetals, and Metalloids

• Horizontal rows are called periodsperiods

• There are 7 periods11

22

33

44

55

66

77

• The 18 vertical columns are called families families or groupsgroups.

• Elements are placed in columns by similar properties.

Group Numbers on the Periodic Table

Group Names

Alkali Metals Alkaline Earth Metals

HalogensNoble Gases

Lanthanides

Actinides

ChalcogensChalcogens

Solid, Liquid, and Gaseous Solid, Liquid, and Gaseous ElementsElements

Periodic Periodic TrendsTrends

Periodic TrendsPeriodic Trends• Atomic radiusAtomic radius: the distance from the

center of an atom's nucleus to its outermost electron.

• Since the electron cloud does not have an exact boundary, the atomic radius is usually measured by finding the distance between the centers of two atoms.

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2

3

4 5

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7

• Atomic Radius– Increases to the LEFT and DOWN

Atomic RadiusAtomic Radius

Periodic TrendsPeriodic Trends• Ionic Size:Ionic Size: Atoms gain or lose electrons

to gain noble gas configurations, or pseudonoble gas configurations.

• Metals loselose outer electrons forming cations which are smaller than the atoms they were made from.

• Nonmetals gaingain outer electrons forming anions which are larger than the atoms they were made from.

• Ionic Radius– Cations (+)

• lose e-

– smallersmaller

© 2002 Prentice-Hall, Inc.

– Anions (–)• gain e

• largerlarger

Ionic RadiusIonic Radius

Periodic TrendsPeriodic Trends• Ionization energy:Ionization energy: the energy

required to remove an electron from a gaseous atom or ion.

• Removing one electron makes a +1 ion.

• The energy required is called the first ionization energyfirst ionization energy.

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2

3

4 5

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• Ionization Energy– Increases UP and to the RIGHT

Ionization EnergyIonization Energy

Periodic TrendsPeriodic Trends• Electron AffinityElectron Affinity: a measure of

an atom's attraction, or affinity, for an extra electron.

Periodic TrendsPeriodic Trends• Atoms that have a greater

attraction for an added electron have a more negative electron affinity.

• The higher the electron affinity, the higher the negative value. Nonmetals, other than the noble gases, have the greatest electron affinities.

Electron AffinityElectron Affinity::• Electron affinity generally

decreases down a groupdecreases down a group since the attraction by the nucleus on the outer level electron is weakened by the increase in atomic size.

• Electron affinity generally increases across a periodincreases across a period because the atoms become smaller and the nuclear charge increases.

Periodic TrendsPeriodic Trends• Activity:Activity: refers to the tendency of an atom to

react.• Activity increasesincreases toward the lower left side of the

periodic table, for metals.• Activity increasesincreases toward the upper right corner

of the periodic table, except the noble gases, for nonmetals.

• Fluorine Fluorine is the most active element. It reacts with everything except He, Ne, and Ar.

• Noble gases are generally very unreactive.

STOP PresentationSTOP Presentation

Pass out Periodic Trends worksheet to the students.

Please read the instructions at the top of worksheet.

Once students have had time to complete the worksheet, please continue to show this presentation for the answers.

Answers: Trends from Answers: Trends from the Periodic Tablethe Periodic Table

#1 What do you expect #1 What do you expect the following atoms to do the following atoms to do when bonding with other when bonding with other

atoms?atoms?

Bonding Atom ReasonBonding Atom Reason

1. Calcium-A-Lose electrons

2. Fluorine-B-Gain electrons

3. Neon-C- Neither lose or gain electrons

4. Argon-C-Neither lose or gain electrons

5. Oxygen-B-Gain electrons

1. Calcium is a metal

2. Fluorine is a nonmetal

3. Neon is a noble gas

4. Argon is a noble gas

5. Oxygen is a nonmetal

Bonding Atom ReasonBonding Atom Reason

6. Zinc-A-Lose electrons

7. Lithium-A-Lose electrons

8. Sulfur-B-Gain electrons

9. Helium-C-Neither lose or gain electrons

10. Sodium-A-Lose electrons

6. Zinc is a metal

7. Lithium is a metal

8. Sulfur is a nonmetal

9. Helium is a noble gas

10. Sodium is a metal

#2 Predict the ions #2 Predict the ions formed by the following formed by the following

elementselements

Ion formation ReasonIon formation Reason

1. Aluminum, Al +3

1. Aluminum is a metal-which means it loses electrons. It is in Group IIIA (look at the top of the column in which Aluminum is under) It has 3 valence electrons. It needs to lose three electrons in order to have the valence electrons of the noble gas Neon (which has 8 valence electrons). Because it loses 3 electrons it the ion is positively charged.

Ion Formation ReasonIon Formation Reason

2. Phosphorus, P -3 2. Phosphorus is a nonmetal-which mean it gains electrons. It is in Group VA. It has 5 valence electrons; therefore it needs 3 more electrons in order to have the valence electrons of the noble gas Neon (which has 8 valence electrons). It is -3 because electrons are negatively charged.

Ion Formation ReasonIon Formation Reason

3. Nitrogen, N -3 3. Nitrogen is a nonmetal-which mean it gains electrons. It is in Group VA. It has 5 valence electrons; therefore it needs 3 more electrons in order to have the valence electrons of the noble gas Neon (which has 8 valence electrons). It is -3 because electrons are negatively charged.

Ion Formation ReasonIon Formation Reason

4. Lead, Pb +4 4. Lead is a metal-which means it loses electrons. It is in Group IVA. It has 4 valence electrons. It needs to lose four electrons in order to have the valence electrons of the noble gas Xeon (which has 8 valence electrons). Because it loses 4 electrons, the ion is positively charged.

#3 Predict the number of #3 Predict the number of valence electrons the valence electrons the

following atoms.following atoms.

Valence Number ReasonValence Number Reason

1. Tin, Sn 4

2. Bismuth, Bi 5

1. Tin is a member of group IVA. Which means it has 4 valence electrons

2. Bismuth is a member of group VA. Which means it has 5 valence electrons.

Valence Number Valence Number ReasonReason

3. Silicon, Si 4

4. Strontium, Sr 2

3. Silicon is a member of IVA. Which means it has 4 valence electrons.

4. Strontium is a member of IIA. Which means it has 2 valence electrons.

Predict the following electron Predict the following electron configurationconfiguration

4. Aluminum: 1s22s22p63s23p1

5. Bromine: 1s22s22p63s23p64s23d104p5

Prediction for new element, Prediction for new element, atomic number 114atomic number 114

6. Metal: Since it would be in the same column as Lead-which is a metal. It would lose electrons, be a good conductor of heat and electricity, have luster, be ductile and malleable.

7. The number of valence electrons for the new element 114 is 4 valence electrons, because it would be in column IV-which has 4 valence electrons.

8. The ion formation of the new element 114 is +4.

A new element, atomic number A new element, atomic number 118, was discovered. 118, was discovered.

9. Predict some properties of this element.

It would be a noble gas, be relatively unreactive, have 8 valence electrons, form no ions.