The Periodic Table & The Periodic Table & Formation of IonsFormation of Ions

Mendeleev: Mendeleev: Considered to be the father of the periodic tableConsidered to be the father of the periodic table Arranged elements by increasing atomic massArranged elements by increasing atomic mass Placed elements with similar properties in Placed elements with similar properties in

columnscolumns Left blank spaces for undiscovered elementsLeft blank spaces for undiscovered elements Was able to accurately predict properties of the Was able to accurately predict properties of the

undiscovered elementsundiscovered elements

Development of the Periodic TableDevelopment of the Periodic Table

MoseleyMoseley Arranged elements by increasing atomic Arranged elements by increasing atomic

numbernumber Gave a clearer pattern of periodic propertiesGave a clearer pattern of periodic properties Periodic Law: there is a periodic repetition of Periodic Law: there is a periodic repetition of

chemical and physical properties of elements chemical and physical properties of elements when they are arranged by increasing atomic when they are arranged by increasing atomic numbernumber

The Modern Periodic TableThe Modern Periodic Table

Groups/FamiliesGroups/Families Columns of elementsColumns of elements Numbered 1 to 18Numbered 1 to 18 Elements have similar properties Elements have similar properties Elements have the same # of valence electronsElements have the same # of valence electrons

PeriodsPeriods Rows of elementsRows of elements Numbered 1 to 7Numbered 1 to 7 Corresponds to number of energy levels of an atomCorresponds to number of energy levels of an atom

Arrangement of the tableArrangement of the table

Groups with Special NamesGroups with Special Names

Group 1:Group 1: Alkali MetalsAlkali Metals

Group 2: Group 2: Alkaline Earth MetalsAlkaline Earth Metals

Groups 3 -12:Groups 3 -12: Transition MetalsTransition Metals

Group 17Group 17 HalogensHalogens

Group 18Group 18 Noble GasesNoble Gases

Group #Group # # of valence electrons# of valence electrons

11 11

22 22

3-123-12 variesvaries

1313 33

1414 44

1515 55

1616 66

1717 77

1818 88

Each group contains elements with the Each group contains elements with the same number of valence electronssame number of valence electrons

Example 1Example 1

Without drawing electron configurations, Without drawing electron configurations, determine the number of valence electrons determine the number of valence electrons for each of the following:for each of the following: A. CalciumA. Calcium B. NeonB. Neon C. SodiumC. Sodium D. AluminumD. Aluminum E. SulfurE. Sulfur

Valence electronsValence electrons

Atomic RadiusAtomic Radius

Ionization Energy: Energy required to Ionization Energy: Energy required to remove an electron from a neutral atomremove an electron from a neutral atom

Electronegativity: The attraction of an Electronegativity: The attraction of an atom for shared electrons in a covalent atom for shared electrons in a covalent bondbond

Periodic TrendsPeriodic Trends

Atomic RadiusAtomic Radius

Increases from top to bottom in a groupIncreases from top to bottom in a group

Decreases from left to right across a Decreases from left to right across a periodperiod

Example 2Example 2

Arrange each of the following in order of Arrange each of the following in order of increasing atomic radius (smallest increasing atomic radius (smallest largest)largest) A. Calcium, Magnesium, BariumA. Calcium, Magnesium, Barium B. Fluorine, Iodine, ChlorineB. Fluorine, Iodine, Chlorine C. Calcium, Arsenic, BromineC. Calcium, Arsenic, Bromine D. Chlorine, Fluorine, OxygenD. Chlorine, Fluorine, Oxygen

Ionization EnergyIonization Energy

Increases from left to right across a periodIncreases from left to right across a period

Decreases from top to bottom in a groupDecreases from top to bottom in a group

Example 3Example 3

Place the following in order of increasing Place the following in order of increasing ionization energy (lowest ionization energy (lowest highest) highest) A. Sulfur, Oxygen, SeleniumA. Sulfur, Oxygen, Selenium B. Calcium, Magnesium, BerylliumB. Calcium, Magnesium, Beryllium C. Lithium, Fluorine, NitrogenC. Lithium, Fluorine, Nitrogen D. Carbon, Silicon, NitrogenD. Carbon, Silicon, Nitrogen

ElectronegatvityElectronegatvity

Increases from left to right across a periodIncreases from left to right across a period

Decreases from top to bottom in a groupDecreases from top to bottom in a group

Example 4Example 4

Determine the most electronegative Determine the most electronegative element in each pairelement in each pair A. Calcium, sulfurA. Calcium, sulfur B. sulfur, chlorineB. sulfur, chlorine C. potassium, bromineC. potassium, bromine D. Silicon, phosphorusD. Silicon, phosphorus

Octet RuleOctet Rule

Typically, elements want to have 8 Typically, elements want to have 8 valence electrons (except hydrogen and valence electrons (except hydrogen and helium) in order to be stablehelium) in order to be stable

Noble gases are stable because they have Noble gases are stable because they have 8 valence electrons8 valence electrons

Other elements will lose, gain, or share Other elements will lose, gain, or share electrons in order to have 8 valenceelectrons in order to have 8 valence

Becoming StableBecoming Stable

Remember atoms are neutral because Remember atoms are neutral because they have equal #’s of protons and they have equal #’s of protons and electronselectrons

When an atom gains or loses electrons, When an atom gains or loses electrons, this equality is upset…this equality is upset…

The atom is no longer neutral…and is no The atom is no longer neutral…and is no longer called an atomlonger called an atom

IonsIons

An ion is an atom that has an electric An ion is an atom that has an electric charge because it has lost or gained charge because it has lost or gained electronselectrons

If an atom loses electrons, its charge will If an atom loses electrons, its charge will become positive. It is called a cation.become positive. It is called a cation.

If an atom gains electrons, its charge will If an atom gains electrons, its charge will become negative. It is called an anion.become negative. It is called an anion.

On the Periodic TableOn the Periodic Table

Group Group Charge of IonCharge of Ion

11 + 1+ 1

22 + 2+ 2

3 -123 -12 VariesVaries

1313 + 3 + 3

1414

1515 - 3- 3

1616 - 2- 2

1717 - 1- 1

1818 Do not form ionsDo not form ions

Ionic ChargesIonic Charges

The number of electrons that an atom will The number of electrons that an atom will gain or lose in order to become stable gain or lose in order to become stable determines its ionic chargedetermines its ionic charge

Metals lose electrons and have + charge Metals lose electrons and have + charge (These are called cations)(These are called cations)

Nonmetals gain electrons and have – Nonmetals gain electrons and have – charge (These are called anions)charge (These are called anions)

Size of IonsSize of Ions

Cations (+ charges) are smaller than their Cations (+ charges) are smaller than their parent atomsparent atoms

Anions (- charges) are larger than their Anions (- charges) are larger than their parent atomsparent atoms

Example 5Example 5

Determine the ionic charge for each of the Determine the ionic charge for each of the following. Indicate if it is a cation or an following. Indicate if it is a cation or an anion:anion: A. MagnesiumA. Magnesium B. ChlorineB. Chlorine C. OxygenC. Oxygen D. SodiumD. Sodium E. NitrogenE. Nitrogen

Naming IonsNaming Ions

If the ion is positive…name it the atom’s If the ion is positive…name it the atom’s name followed by the word ionname followed by the word ion Example: Sodium is NaExample: Sodium is Na1+1+…its name is Sodium …its name is Sodium

ionion

If the ion is negative…change the atom’s If the ion is negative…change the atom’s name to have an –ide ending then write the name to have an –ide ending then write the word ionword ion Example: Chlorine is ClExample: Chlorine is Cl1-1-…its name is chloride …its name is chloride

ionion

Example 6Example 6

Indicate the ionic charge and the name of Indicate the ionic charge and the name of the ion formed from each of the following the ion formed from each of the following elements:elements: A. PotassiumA. Potassium B. BromineB. Bromine C. AluminumC. Aluminum D. CesiumD. Cesium E. FluorineE. Fluorine

Element Mg F O K Na Al

# Valence electrons

Ionic Charge

Symbol

Name of ion

# of protons

# of electrons