What do the numbers mean? Na 11 22.990 sodium This is the atomic number. It is the number of protons in a single atom of this element. It is also #

What do the numbers What do the numbers mean?mean?

Na

11

22.990

sodium

This is the atomic number. It is the number of protons in a single atom of this element. It is also # of electrons.

The symbol for this element.

This is the average atomic mass, it is the number of protons + neutrons, or the mass of the nucleus of an atom.

This is the name of the element.

PeriodsPeriods Horizontal rows on the tableHorizontal rows on the table Correspond to the outermost Correspond to the outermost

energy level of electrons being energy level of electrons being filled.filled.

GroupsGroups Vertical columns on the tableVertical columns on the table All groups have number designationsAll groups have number designations Are also called familiesAre also called families Same/similar physical and chemical

properties due to VALENCE ELECTRONS! Some groups have special family names Some groups have special family names

based upon characteristics of elements based upon characteristics of elements in that groupin that group

Regions of the Periodic Regions of the Periodic TableTable

MetalsMetals NonmetalsNonmetals Metalloids (semi-Metalloids (semi-

conductors)conductors) Transition metalsTransition metals Inner-transition metalsInner-transition metals

Lanthanide SeriesLanthanide Series Actinide SeriesActinide Series

Transuranium elementsTransuranium elements

MetalsMetals

Properties of element Properties of element types: types:

1) 1) MetalsMetals- high luster, good conductors, - high luster, good conductors, ductile, malleable, most are solid at room ductile, malleable, most are solid at room temp (except Hg is liquid)temp (except Hg is liquid)

2)2)NonmetalsNonmetals- low luster, poor conductors, - low luster, poor conductors, very brittle, various states of matter at very brittle, various states of matter at room temperature (ex: S is solid, O is gas, room temperature (ex: S is solid, O is gas, Br is liquid)Br is liquid)

3) 3) Semi-Conductors Semi-Conductors - sit on stair-step line - sit on stair-step line metals and non-metals; have properties metals and non-metals; have properties between metals and non-metalsbetween metals and non-metals

NonmetalsNonmetals

Semi ConductorsSemi Conductors

Transition MetalsTransition Metals

Inner-Transition MetalsInner-Transition Metals

Regions of the Regions of the Periodic Table Periodic Table

ContinuedContinued Radioactive elements ( atomic # > 83)Radioactive elements ( atomic # > 83) Most active metals (Fr)Most active metals (Fr) Most active nonmetals (F)Most active nonmetals (F)

(A) Periods of the periodic table, and (A) Periods of the periodic table, and (B) groups of the periodic table. (B) groups of the periodic table.

Family NamesFamily Names Alkali Metals (Group 1)Alkali Metals (Group 1) Alkaline Earth Metals (Group 2)Alkaline Earth Metals (Group 2) Halogens (Group 7)Halogens (Group 7) Noble gases (Group 8)Noble gases (Group 8)

Alkali Metals (Group 1)Alkali Metals (Group 1)

Form metal hydroxides (strong bases) Form metal hydroxides (strong bases) when reacting in waterwhen reacting in water 2 Na + 2 HOH 2 Na + 2 HOH 2 NaOH + H 2 NaOH + H22

Are generally very reactive compared to Are generally very reactive compared to other groups of metalsother groups of metals

Have Have one valence electronone valence electron Form cations with a Form cations with a +1 charge+1 charge

Alkali metalsAlkali metals

Alkaline Earth Metals Alkaline Earth Metals (Group 2)(Group 2)

Form metal hydroxides (strong Form metal hydroxides (strong bases) when reacting in waterbases) when reacting in water Ca + 2 HOH Ca + 2 HOH Ca(OH) Ca(OH)22 + H + H22

Are not as reactive as alkali metals Are not as reactive as alkali metals but are generally more reactive than but are generally more reactive than transition elementstransition elements

Have two valence electronsHave two valence electrons Form cations with a +2 chargeForm cations with a +2 charge

Alkaline earth metalsAlkaline earth metals

Halogens (Group 7)Halogens (Group 7)

Form a multitude of saltsForm a multitude of salts Are generally very reactive when Are generally very reactive when

compared to other nonmetalscompared to other nonmetals Have seven valence electronsHave seven valence electrons Form anions with a -1 chargeForm anions with a -1 charge

HalogensHalogens

Noble Gases (Group 8)Noble Gases (Group 8)

Are generally unreactive (inert)Are generally unreactive (inert) Have eight valence electronsHave eight valence electrons Some compounds with xenon and Some compounds with xenon and

krypton have been synthesizedkrypton have been synthesized

Nobel Gases – Group 18 Nobel Gases – Group 18

Atomic RadiusAtomic Radius Ionization EnergyIonization Energy Electron AffinityElectron Affinity Ionic RadiusIonic Radius ElectronegativityElectronegativity Metallic CharacterMetallic Character Nonmetallic CharacterNonmetallic Character

Atomic Radii Trends on Atomic Radii Trends on the Periodic Tablethe Periodic Table

For the main For the main group elements:group elements:

atomic radii atomic radii increase going increase going down a groupdown a group

decrease going decrease going across a period.across a period.

Going down a group radii Going down a group radii increases because: increases because:

Energy level is added for each Energy level is added for each successive periodsuccessive period

Ionization EnergyIonization Energy

Is defined as the energy required to Is defined as the energy required to remove an electron from an atom remove an electron from an atom in the gas phase.in the gas phase.

Each atom can have a series of Each atom can have a series of ionization energies, since more ionization energies, since more than one electron can always be than one electron can always be removed (except H).removed (except H).

First Ionization Energy Trends on First Ionization Energy Trends on the Periodic Tablethe Periodic Table

First ionization energies generally increase First ionization energies generally increase across a period and decrease down a group. across a period and decrease down a group.

Generally, the larger the atom the easier it is Generally, the larger the atom the easier it is to remove an electron and the less to remove an electron and the less ionization energy required. ionization energy required.

WHY? The outermost electrons are found in WHY? The outermost electrons are found in higher energy levels as one goes down the higher energy levels as one goes down the group. Since the electrons are farther from group. Since the electrons are farther from the nucleus's pull the electrons are more the nucleus's pull the electrons are more easily removed.easily removed.

Ability to lose an electron Ability to lose an electron by typeby type

Low ionization energies are Low ionization energies are typical of active metals.typical of active metals.

High ionization energies are High ionization energies are typical of active nonmetals.typical of active nonmetals.

Very high ionization energies are Very high ionization energies are found with the Noble Gasesfound with the Noble Gases

Plot of First Ionization Plot of First Ionization Energies For Periods 1-4Energies For Periods 1-4

Ioni

zatio

n E

nerg

y (k

J/m

ol)

Ionic RadiiIonic Radii

Cations (+) have Cations (+) have lostlost one or more one or more electronselectrons and are smaller than and are smaller than the atoms from which they were the atoms from which they were derived.derived.

Anions (-) have Anions (-) have gainedgained one or one or more more electronselectrons and are larger and are larger than the atoms from which they than the atoms from which they were derived.were derived.

WHY?WHY? Electron-electron repulsion Electron-electron repulsion forces spread them further apart. forces spread them further apart. Electrons outnumber protons; the Electrons outnumber protons; the protons cannot pull the extra protons cannot pull the extra electrons as tightly toward the electrons as tightly toward the nucleus.nucleus.

Anions (negative ions) are Anions (negative ions) are larger than their respective larger than their respective atoms.atoms.

WHY?WHY? Protons outnumber electrons; the Protons outnumber electrons; the protons can pull the fewer electrons protons can pull the fewer electrons toward the nucleus more tightly. If the toward the nucleus more tightly. If the electron that is lost is the only valence electron that is lost is the only valence electron so that the electron electron so that the electron configuration of the cation is like that of configuration of the cation is like that of a noble gas, then an entirea noble gas, then an entire energy level energy level is lostis lost.  In this case, the radius of the .  In this case, the radius of the cation is much smaller than its cation is much smaller than its respective atom.respective atom.

Cations (positive ions) are Cations (positive ions) are smaller than their respective smaller than their respective atoms.atoms.

Metallic CharacterMetallic Character

Is associated with:Is associated with:• Larger atomic radiiLarger atomic radii• Lower ionization energiesLower ionization energies• Lower electron affinitiesLower electron affinities• Lower electronegativitiesLower electronegativities

The most active metals (ones with The most active metals (ones with the most metallic character) are the most metallic character) are located in the lower left corner of the located in the lower left corner of the table.table.

Nonmetallic CharacterNonmetallic Character

Is associated with:Is associated with:• Smaller atomic radiiSmaller atomic radii• Higher ionization energiesHigher ionization energies• Higher electron affinitiesHigher electron affinities• Higher electronegativitiesHigher electronegativities

The most active nonmetals are The most active nonmetals are found in the upper right hand found in the upper right hand corner of the periodic table corner of the periodic table (excluding the Noble gases).(excluding the Noble gases).

What About the Noble What About the Noble Gases?Gases?

do not behave as metals or nonmetals.do not behave as metals or nonmetals. very high ionization energies and very high ionization energies and

positive electron affinity values.positive electron affinity values. Noble gases usually are not assigned Noble gases usually are not assigned

electronegativities due to their electronegativities due to their tendency to tendency to notnot form chemical bonds. form chemical bonds.

Have full valence electron shells so Have full valence electron shells so they do not tend to form compounds at they do not tend to form compounds at all. all.

Chemical ReactivityChemical Reactivity

Metals Metals increase in increase in reactivity left reactivity left and down. and down.

Nonmetals Nonmetals become more become more reactive up reactive up and to the and to the right. right.

Most reactive Most reactive metal is? metal is?

Most reactive Most reactive nonmetal is? nonmetal is?

Fr

F