The Periodic Table

Early Organization As early as the early Greeks, scientists wanted to organize. As early as the early Greeks, scientists wanted to organize. They separated matter into Earth, Air, Fire and Water. They separated matter into Earth, Air, Fire and Water. They even had more detail such as combinations. They even had more detail such as combinations. For example: Earth and Fire = Lava For example: Earth and Fire = Lava Check out the game Little Alchemy on GOOGLE – you might like it. Check out the game Little Alchemy on GOOGLE – you might like it.

History of the Periodic Table In the 1700s scientists had identified only 30 elements In the 1700s scientists had identified only 30 elements In the 1800s there were 60 In the 1800s there were 60

History of the Periodic Table Early 1800s Dobereiner grouped elements into triads Early 1800s Dobereiner grouped elements into triads Li, Na, K Li, Na, K

History of the Periodic Table 1865 J.A.R. Newlands discovered properties repeated themselves every eighth element 1865 J.A.R. Newlands discovered properties repeated themselves every eighth element Called these octaves Called these octaves

Mendeleev 1869 Dmitri Mendeleev produced the first periodic table for his students 1869 Dmitri Mendeleev produced the first periodic table for his students Left blanks where elements had yet to be discovered Left blanks where elements had yet to be discovered Was organized by atomic weight as that was the standard at the time. Was organized by atomic weight as that was the standard at the time.

Here is one of the early official versions of Mendeleev’s Periodic Chart Notice it is in German, even though Mendeleev was Russian.

Properties of Germanium as Predicted by Mendeleev Properties of Ekasilicon Predicted in 1871 Atomic weight Density Specific heat Melting point Oxide formula Oxide density Chloride formula bp of chloride g/cm J/(°C · g) Very high RO g/cm 3 RCl 4 100°C

Properties of Germanium Predicted in 1871 Observed in 1886 Atomic weight Density Specific heat Melting point Oxide formula Oxide density Cl -1 formula bp of chloride g/cm J/(°C · g) Very high RO g/cm 3 RCl 4 100°C g/cm J/(°C · g) 960°C GeO g/cm 3 GeCl 4 86°C

HenryMoseley In 1913 Moseley assigned elements atomic numbers and rearranged periodic table. In 1913 Moseley assigned elements atomic numbers and rearranged periodic table.

Table Terms Periodic Law – when arranged by increasing atomic number elements repeat similar chemical and physical properties Periodic Law – when arranged by increasing atomic number elements repeat similar chemical and physical properties Groups or Families are the columns on the periodic table Groups or Families are the columns on the periodic table Periods are the rows going across. Periods are the rows going across.

Major Groups on the Periodic Table Alkali Metals Alkali Metals Alkaline Earth Metals Alkaline Earth Metals Transition Metals Transition Metals Boron Group Boron Group Carbon Group Carbon Group Nitrogen Group Nitrogen Group Oxygen Group (Chalcogens) Oxygen Group (Chalcogens) Halogens Halogens Noble Gases Noble Gases Actinide Series Actinide Series Lanthanide Series Lanthanide Series

Metals, Nonmetals, and Metalloids 6.1 Check out Theodore Gray’s App – The elements

Metals, Nonmetals, and Metalloids 6.1

Metals, Nonmetals, and Metalloids  Metals, Metalloids, and Nonmetals in the Periodic Table 6.1

Metals, Nonmetals, and Metalloids  Metals, Metalloids, and Nonmetals in the Periodic Table 6.1

Metals, Nonmetals, and Metalloids 6.1

Metals Good Conductors of heat and electricity Good Conductors of heat and electricity Luster – Shiny Luster – Shiny Malleable – pounded into thin sheets Malleable – pounded into thin sheets Ductile – pulled into a wire Ductile – pulled into a wire Mercury is the only liquid metal at room temp Mercury is the only liquid metal at room temp

Non-Metals Most are gases Most are gases Solids are brittle (S & P) Solids are brittle (S & P) Bromine is the only liquid nonmetal at room temp Bromine is the only liquid nonmetal at room temp

Metalloids Properties of metals and non-metals Properties of metals and non-metals Semi conductors Semi conductors Make very good computer chips Make very good computer chips

Atomic Radius Atomic radius is the distance from the atom’s nucleus to its outer edge. Atomic radius is the distance from the atom’s nucleus to its outer edge. –In the same energy level, more protons exert a stronger pull towards the nucleus

Showing the Trend of Atomic Size

Which has larger atomic radius? Na or Rb Na or Rb P or Cl P or Cl You can tell by looking at the chart and knowing the trend.

Ionization Energy Ionization energy is the energy needed to remove one electron Ionization energy is the energy needed to remove one electron Na (g)  Na +1 (g) + 1 e -1 Na (g)  Na +1 (g) + 1 e -1 Metals are more likely to give up an electron than nonmetals. Metals are more likely to give up an electron than nonmetals.

Trends in Ionization Energy It is good to know that Fluorine has the highest Ionization Energy

Which has larger ionization energy? H or Cs H or Cs Li or N Li or N

Ionic Radius Ionic radius is the distance from the ion’s nucleus to its outer edge. Ionic radius is the distance from the ion’s nucleus to its outer edge. Non-metal ions get larger with a negative charge Non-metal ions get larger with a negative charge Metal ions get smaller with a positive charge Metal ions get smaller with a positive charge This is because more protons are pulling on fewer electrons This is because more protons are pulling on fewer electrons

Anions are going to be larger than the atom. Cations are going to be smaller than the atom.

Trends in Ionic Size  Relative Sizes of Some Atoms and Ions

Which of the following is larger? O or O -2 O or O -2 K or K + K or K +

Any Questions????

Electronegativity Electronegativity reflects an atom’s ability to attract electrons Electronegativity reflects an atom’s ability to attract electrons Cs & Fr have the lowest electronegativities; F has the highest Cs & Fr have the lowest electronegativities; F has the highest

Reactivity of Alkali and Alkaline Earth Metals Metals become more reactive as you move down the group Metals become more reactive as you move down the group Metals become less active when moving left to right Metals become less active when moving left to right

Why Are There Patterns ? Elements have physical and chemical properties based upon their valence electrons. Elements have physical and chemical properties based upon their valence electrons. Valence electrons are the electrons in the outer most energy level (s & p orbitals). Valence electrons are the electrons in the outer most energy level (s & p orbitals). The number of valence electrons may be determined by using the periodic table. The number of valence electrons may be determined by using the periodic table.

Why Are There Patterns? When you look at an atom you are observing the valence electrons When you look at an atom you are observing the valence electrons Duet rule - only 2 electrons fill the first energy level Duet rule - only 2 electrons fill the first energy level Octet rule – 8 valence electrons is considered to be a full set Octet rule – 8 valence electrons is considered to be a full set

Electron Affinity Electron affinity is the energy change that occurs when an atom gains an electron. Electron affinity is the energy change that occurs when an atom gains an electron. F (g) + e -1  F -1 (g) F (g) + e -1  F -1 (g) Most atoms give off energy when an electron is gained (negative). Most atoms give off energy when an electron is gained (negative). Nonmetals have more of an electron affinity than metals. Nonmetals have more of an electron affinity than metals. EA decreases when moving down the group. EA decreases when moving down the group. EA increases moving from left to right in a period. EA increases moving from left to right in a period.