Periodic Table of Elements

Bohr Model: and Valence electrons Bohr Model: and Valence electrons Casseopia Dan Radcliffe Dan Radcliffe Bald Guy: Bald Guy: Song: Song:

Dmitri Mendeleev Russian chemist. Russian chemist. Created first version of the periodic table. Created first version of the periodic table. Predicted properties of elements yet to be discovered. Predicted properties of elements yet to be discovered. Rockin the shaggy beard…

Mendeleev arranged elements according to their atomic weights. Mendeleev arranged elements according to their atomic weights. Today they are arranged by atomic number. Today they are arranged by atomic number.

Periodic Law Properties of elements are periodic functions of their atomic numbers. Properties of elements are periodic functions of their atomic numbers. In other words, properties tend to repeat as you start a new period. In other words, properties tend to repeat as you start a new period.

Groups/Families Columns on the table (1-18). Columns on the table (1-18). Elements have the same number of valence electrons. Elements have the same number of valence electrons. Similar chemical properties. Similar chemical properties. Tend to form bonds in a similar way to get stable octet. Tend to form bonds in a similar way to get stable octet.

Periods (1-7) The rows on the table. The rows on the table. Have the same number of occupied energy levels. Have the same number of occupied energy levels. They do not have similar properties. They do not have similar properties.

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Alkali Metals 1 valence electron 1 valence electron Form +1 Ions Form +1 Ions Very reactive Very reactive Found only in compounds. Found only in compounds.

Rubidium

Comparing the Alkali Metals

Alkaline Earth Metals 2 valence electrons 2 valence electrons Form +2 ions Form +2 ions Very reactive Very reactive Found only in compounds Found only in compounds

Halogens 7 valence electrons 7 valence electrons Form -1 ions Form -1 ions Very reactive Very reactive All nonmetals All nonmetals

IODINE solid → gas (sublimes) GasLiquidSolid FLUORINE Extremely reactive gas

Noble Gases Inert Gases Inert Gases Not reactive Not reactive Have stable octet Have stable octet (except He) Monoatomic gases Monoatomic gases

s, p, d, f, “Blocks” Indicates what sublevel is being filled last in the atom Indicates what sublevel is being filled last in the atom

Transition Metals Metals in the “lower” columns. Metals in the “lower” columns. (d-block metals) “Inner” transition metals are the two bottom rows “Inner” transition metals are the two bottom rows (f-block metals) (f-block metals)

Transition Metals Form colored compounds and solutions. Form colored compounds and solutions.

Metals/Nonmetals/Metalloids

Metals Have luster Have luster Malleable Malleable Ductile Ductile Conduct heat and electricity Conduct heat and electricity Tend to lose valence electrons and form positive ions Tend to lose valence electrons and form positive ions All solids (except Hg) All solids (except Hg)

Nonmetals No luster No luster Brittle (if solid) Brittle (if solid) Don’t conduct Don’t conduct Tend to gain valence electrons Tend to gain valence electrons and form negative ions Can be solid ( I, C, P, S), liquid (Br), Can be solid ( I, C, P, S), liquid (Br), or gases (F, Cl, N, O) Hydrogen is considered a nonmetal Hydrogen is considered a nonmetal

Metalloids (Semimetals) Most elements along the “staircase” Most elements along the “staircase” Can have properties of both metals and nonmetals. Can have properties of both metals and nonmetals. B, Si, Ge, As, Sb, Te, At B, Si, Ge, As, Sb, Te, At

Trends in the Period Table

Atomic Radius Distance from the nucleus of an atom to the outer edge of it’s electron cloud. Distance from the nucleus of an atom to the outer edge of it’s electron cloud.

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Trends in Radius Down a Group Down a Group Ex: Group 1 What happens? Across a Period Across a Period Ex: Period 2What happens? Li Na K Rb Cs Fr LiBeBCNOFNe

Down a Group Down a Group Size increases Size increases Why? Why? You add new energy levels Across a Period Across a Period Size decreases Size decreases Why? Why? Increasing nuclear charge pulls on the energy levels

Ionization Energy Energy required to remove the outermost electron from an atom. Energy required to remove the outermost electron from an atom.

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Trends in Ionization Energy Down a Group Down a Group Ex: Group 1 What happens? Across a Period Across a Period Ex: Period 2What happens? Li Na K Rb Cs Fr LiBeBCNOFNe

What is the trend? Directly related to Atomic Radius. Large Radius = Lower Ionization Energy Large Radius = Lower Ionization EnergyWhy? The further the outmost electron to the nuclear pull the easier to remove it.

Electronegativity The relative attraction an atom has for electrons involved in bond formation. The relative attraction an atom has for electrons involved in bond formation.

The higher the EN value the more the atom “pulls” on electrons involved in a bond. The higher the EN value the more the atom “pulls” on electrons involved in a bond. This can result in “polar” and “nonpolar” bonds. This can result in “polar” and “nonpolar” bonds.

Fluorine has the highest EN value = 4 Fluorine has the highest EN value = 4 (The EN scale was created by comparing other elements to Fluorine)

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Trends in Electronegativity Down a Group Down a Group Ex: Group 1 What happens? Across a Period Across a Period Ex: Period 2What happens? Li Na K Rb Cs Fr LiBeBCNOFNe

Metallic/NonMetallic Character More “Metallic”: More “Metallic”: Large radius Large radius Low Ionization Energy Low Ionization Energy Low Electronegativity Low Electronegativity More “Non Metallic”: More “Non Metallic”: Small radius Small radius High Ionization Energy High Ionization Energy High Electronegativity High Electronegativity