The Periodic Table Applied Chemistry

Elements There are approximately 116 elements in the periodic table. There are approximately 116 elements in the periodic table. 92 elements occur naturally in nature. 92 elements occur naturally in nature. Elements exist in the following three states: solid, liquid, and gas Elements exist in the following three states: solid, liquid, and gas Elements can be found in all matter, including living things and the environment Elements can be found in all matter, including living things and the environment All elements can be located in the periodic table. All elements can be located in the periodic table.

Properties of Elements Qualitative Properties: properties describing appearance; descriptive using 5 senses Qualitative Properties: properties describing appearance; descriptive using 5 senses Examples: Texture, color, shape, odor Examples: Texture, color, shape, odor Quantitative Properties: properties involving measurements (numbers) Quantitative Properties: properties involving measurements (numbers)

Quantitative Properties Melting point – Temperature at which a solid changes to a liquid ( +*/5701-+*3 ) Melting point – Temperature at which a solid changes to a liquid ( +*/5701-+*3 ) Boiling point – Temperature at which a liquid changes to a gas ( o C). Boiling point – Temperature at which a liquid changes to a gas ( o C). Density – a measure of the amount of mass of an object divided by its volume Density – a measure of the amount of mass of an object divided by its volume Units are grams per milliliter (g/mL) Units are grams per milliliter (g/mL)

Properties of Metals At room temp, all are solid except for mercury. At room temp, all are solid except for mercury. Luster (A.K.A. Shininess) Luster (A.K.A. Shininess) Good conductors of heat and electricity. Good conductors of heat and electricity. High density (ex. Dumbbell) High density (ex. Dumbbell) High melting points High melting points

Properties of Metals Ductile: can be drawn out into thin wires. Ductile: can be drawn out into thin wires. Malleable: can be hammered into thin sheets. Malleable: can be hammered into thin sheets. Metals are found on the left side of the periodic table. Metals are found on the left side of the periodic table. Metals make up most of the periodic table. Metals make up most of the periodic table.

Nonmetals At room temperature, they are solids, liquids, or gases. At room temperature, they are solids, liquids, or gases. No luster (dull). No luster (dull). Insulators of heat and electricity. (Do not allow heat and electricity to flow through them.) Insulators of heat and electricity. (Do not allow heat and electricity to flow through them.) Brittle, easy to break Brittle, easy to break Neither malleable or ductile Neither malleable or ductile Lower boiling points and melting points than metals. Lower boiling points and melting points than metals. Located on the upper right side of the periodic table. Located on the upper right side of the periodic table.

Sulfur Iodine

Metalloids (Semimetals) Have properties of both metals and nonmetals. Have properties of both metals and nonmetals. There are 7 metalloids in the periodic table: Boron, Silicon, Germanium, Arsenic, Antimony, Tellurium, & Astatine. There are 7 metalloids in the periodic table: Boron, Silicon, Germanium, Arsenic, Antimony, Tellurium, & Astatine. Located between the metals and nonmetals, ALONG the staircase. Located between the metals and nonmetals, ALONG the staircase.

The Periodic Table

History of the Periodic Table Periodic – repeating pattern Periodic – repeating pattern Dobereiner (1829): found that some elements have similar properties. Dobereiner (1829): found that some elements have similar properties. Grouped the elements in groups of three called triads. Grouped the elements in groups of three called triads.

Triads on the Periodic Table

Newlands (1867): saw that the properties of elements repeat every 8 element. Newlands (1867): saw that the properties of elements repeat every 8 element. This is called the Law of Octaves. This is called the Law of Octaves. History of the Periodic Table

Mendeleev: developed the first periodic table in Mendeleev: developed the first periodic table in Arranged the periodic table in order of increasing atomic mass. Arranged the periodic table in order of increasing atomic mass.

Dimitri Mendeleev: 1869 Predicted the properties of undiscovered elements and left blank spots in the periodic table for these elements. Predicted the properties of undiscovered elements and left blank spots in the periodic table for these elements. 1 st Periodic Law: the properties of elements recur at certain intervals of increasing atomic mass. 1 st Periodic Law: the properties of elements recur at certain intervals of increasing atomic mass.

History of the Periodic Table Moseley (1911), he reorganized the periodic table in order of increasing atomic number (protons). Moseley (1911), he reorganized the periodic table in order of increasing atomic number (protons). Modern Periodic Law – the properties of elements recur at certain intervals of atomic number. Modern Periodic Law – the properties of elements recur at certain intervals of atomic number. “Properties are periodic” “Properties are periodic”

Organization of the Periodic Table Period: Horizontal Rows in the periodic table Period: Horizontal Rows in the periodic table There are 7 periods in the periodic table. There are 7 periods in the periodic table. Elements in a period do NOT have similar properties. Elements in a period do NOT have similar properties.

Group or Family: Vertical Columns in the periodic table Group or Family: Vertical Columns in the periodic table There are 18 groups in the periodic table. There are 18 groups in the periodic table. Numbered from 1 to 18 or 1A, 2A, (B groups), 3A through 8A. Numbered from 1 to 18 or 1A, 2A, (B groups), 3A through 8A. Elements in the same group have similar properties. Elements in the same group have similar properties. Organization of the Periodic Table

Elements in the same group have similar properties. Why? Elements in the same group have similar properties. Why? Elements in the same group have the same number of VALENCE electrons. Elements in the same group have the same number of VALENCE electrons. Valence electrons are those electrons in the outer energy level. Valence electrons are those electrons in the outer energy level. The maximum number of valence electrons is 8. The maximum number of valence electrons is 8. Organization of the Periodic Table

1A 1 2A 2 3A 4A 5A 6A 7A A 18 1 = Alkali Metals and Hydrogen Group 13 = Boron Group 18 = Noble Gas Group 17 = Halogen Group 16 = Oxygen or Chalcogen Group 15= Nitrogen Group 14 = Carbon Group 2 = Alkaline Earth Metals Transition Group Lanthanide Series Actinide Series Inner Transition

Groups in the periodic table Hydrogen: Group 1 or 1A/IA Hydrogen: Group 1 or 1A/IA 1 valence electron 1 valence electron Alkali Metals: Group 1 or 1A/IA Alkali Metals: Group 1 or 1A/IA 1 valence electron 1 valence electron Most reactive metals Most reactive metals As you go down a group, reactivity increases. As you go down a group, reactivity increases.

Groups in the periodic table Alkaline Earth Metals: Group 2 or 2A/IIA Alkaline Earth Metals: Group 2 or 2A/IIA 2 Valence electrons 2 Valence electrons Very reactive Very reactive Boron Group: Group 13 or 3A/IIIA Boron Group: Group 13 or 3A/IIIA 3 Valence electrons 3 Valence electrons Carbon Group: Group 14 or 4A/IVA Carbon Group: Group 14 or 4A/IVA 4 Valence electrons 4 Valence electrons

Groups in the periodic table Nitrogen Group: Group 15 or 5A/VA Nitrogen Group: Group 15 or 5A/VA 5 Valence electrons 5 Valence electrons Oxygen Group or Chalcogen Group: Group 16 or 6A/VIA Oxygen Group or Chalcogen Group: Group 16 or 6A/VIA 6 Valence electrons 6 Valence electrons Halogen Group: Group 17 or 7A/VIIA Halogen Group: Group 17 or 7A/VIIA 7 Valence electrons 7 Valence electrons Used in photography Used in photography Most reactive nonmetals Most reactive nonmetals

Groups in the periodic table Noble Gas Group – Group 18 or 8A/VIIIA Noble Gas Group – Group 18 or 8A/VIIIA 8 Valence electrons (Helium only has 2) 8 Valence electrons (Helium only has 2) Do not react with other elements: known as INERT Do not react with other elements: known as INERT Have a complete outer shell of electrons known as a full stable octet Have a complete outer shell of electrons known as a full stable octet “Everyone wants to be like a noble gas.” “Everyone wants to be like a noble gas.”

Groups in the periodic table Transition Metals: Groups 3-12 Transition Metals: Groups 3-12 Inner Transition Metals: Bottom of PT Inner Transition Metals: Bottom of PT Lanthanide Series or Rare Earth Elements Lanthanide Series or Rare Earth Elements (Cerium through Lutetium) (Cerium through Lutetium) Actinide Series Actinide Series (Thorium through Lawrencium) (Thorium through Lawrencium) Transuranium Elements: all elements after uranium (atomic #92) Transuranium Elements: all elements after uranium (atomic #92) these elements are manmade elements these elements are manmade elements

Groups in the periodic table IMPORTANT NOTE: Members of a group have similar chemical properties, because they have the same number of valence electrons. IMPORTANT NOTE: Members of a group have similar chemical properties, because they have the same number of valence electrons.

Trends in the Periodic Table The most reactive metals are the alkali metals. The most reactive metals are the alkali metals. Metals become more reactive as you move down a family. Metals become more reactive as you move down a family. The most reactive metal is Francium. The most reactive metal is Francium.

Trends in the Periodic Table The most reactive nonmetals are the halogens. The most reactive nonmetals are the halogens. Nonmetals become less reactive as you move down a family. Nonmetals become less reactive as you move down a family. The most reactive nonmetal is fluorine. The most reactive nonmetal is fluorine.

Trends in the Periodic Table Atomic Radii The distance between the nucleus and the outermost electrons in an atom. The distance between the nucleus and the outermost electrons in an atom. Unit = picometer (pm) Increases as you go down a group. Increases as you go down a group. Decreases as you go left to right across a period. Decreases as you go left to right across a period.

Atomic Radius Examples: Which has a larger atomic radius? Which has a larger atomic radius? Potassium or Cesium Potassium or Cesium Sodium or Chlorine Sodium or Chlorine Silicon or Lead Silicon or Lead Lithium or Oxygen Lithium or Oxygen

Trends in the Periodic Table Ionization Energy The energy needed to remove a valence electron from an atom. The energy needed to remove a valence electron from an atom. Unit = kJ/mol (kilojoules per mole) Increases as you go from left to right across a period. Increases as you go from left to right across a period. Decreases as you go down a group. Decreases as you go down a group.

Ionization Energy of the 1 st 20 Elements

Trends in the Periodic Table Ionization Energy The ionization energy for the noble gases is very high because they do not want to give up any electrons. (They have a stable octet.) The ionization energy for the noble gases is very high because they do not want to give up any electrons. (They have a stable octet.) The energy needed to remove each successive electron increases. The energy needed to remove each successive electron increases.

Ionization Energy Examples: Which has a larger ionization energy? Which has a larger ionization energy? Silicon or chlorine Silicon or chlorine Lithium or rubidium Lithium or rubidium Sulfur or tellurium Sulfur or tellurium Calcium or bromine Calcium or bromine