The Periodic Table Dimitri Mendeleev

I. Periods The rows ( ) on the periodic table are called PERIODS. The rows ( ) on the periodic table are called PERIODS. A. There are 7 periods, just as there are 7 energy levels. B. Each period has a similar e - configuration. * 1 st period: outer e - occupies the 1 s orbital *2 nd period: 2s and 2p orbitals *3 rd period: 3s and 3p orbitals

II. Groups or Families The columns ( ) are called GROUPS or FAMILIES. They usually have similar properties. The columns ( ) are called GROUPS or FAMILIES. They usually have similar properties. There are 18 groups or families. There are 18 groups or families.

III. Classification of Elements A. METALS Found to the left of the staircase Found to the left of the staircase Have luster (shiny) Have luster (shiny) Excellent conductors of electricity Excellent conductors of electricity Ductile (can be rolled into wires Ductile (can be rolled into wires Malleable (can be flattened into sheets) Malleable (can be flattened into sheets) React with water and oxygen in the air and will rust or corrode React with water and oxygen in the air and will rust or corrode LOSE valence electrons LOSE valence electrons

B. NONMETALS –Have no luster –Are not ductile –Are not malleable –Do not react with water and oxygen to rust or corrode –Poor/no conductivity –GAIN electrons

C. METALLOIDS –Have characteristics of both metals and nonmetals –Semi-conductors = o.k. at conducting electricity The elements that are classified as metalloids are: B, Si, Ge, As, Sb, Te, Po, At B, Si, Ge, As, Sb, Te, Po, At ***All elements touching the staircase, EXCEPT FOR aluminum, are metalloids. ***All elements touching the staircase, EXCEPT FOR aluminum, are metalloids.

IV.Main Group or Representative Elements (s- and p-blocks) Groups 1A, 2A, 3A – 8A (13-18) Groups 1A, 2A, 3A – 8A (13-18) A. All elements in each group or family have the same number of outer (valence) electrons. Ex: Group 3A> all elements in that family have the same # of valence electrons, 3. A. All elements in each group or family have the same number of outer (valence) electrons. Ex: Group 3A> all elements in that family have the same # of valence electrons, 3. B. There are 8 groups in the “Representative Elements”. (We will list them below.) B. There are 8 groups in the “Representative Elements”. (We will list them below.)

1. Alkali Metals (Group 1A) Li (lithium) Li (lithium) Na (sodium) Na (sodium) K (potassium) K (potassium) Rb (rubidium) Rb (rubidium) Cs (cesium) Cs (cesium) Fr (francium) Fr (francium)

High reactivity—they are the MOST reactive metals High reactivity—they are the MOST reactive metals Explosive in water Explosive in water Very soft metals Very soft metals React with oxygen in the air React with oxygen in the air Have 1 valence electron Have 1 valence electron Lose 1 electron to become stable and then have a Lose 1 electron to become stable and then have a +1 charge +1 charge Excellent conductors of electricity Excellent conductors of electricity

2.Alkaline-Earth Metals (Group 2A) Be (beryllium) Be (beryllium) Mg (magnesium) Mg (magnesium) Ca (calcium) Ca (calcium) Sr (strontium) Sr (strontium) Ba (barium) Ba (barium) Ra (radium) Ra (radium)

Reactive, but not as reactive as the Gr. 1A Reactive, but not as reactive as the Gr. 1A Harder and stronger than Gr. 1A Harder and stronger than Gr. 1A Have 2 valence electrons Have 2 valence electrons Lose 2 electrons and then have a Lose 2 electrons and then have a +2 charge +2 charge

3.The Boron Family (Group 3A) B (boron – a metalloid) B (boron – a metalloid) Al (aluminum) The rest are metals. Al (aluminum) The rest are metals. Ga (gallium) Ga (gallium) In (indium) In (indium) Tl (thallium) Tl (thallium)

The METALS of this group (all of them except for boron) Have 3 valence electrons Have 3 valence electrons Usually lose 3 electrons Usually lose 3 electrons +3 charge +3 charge

4.The Carbon Family (Group 4A) C (carbon – nonmetal) C (carbon – nonmetal) Si (silicon – metalloid) Si (silicon – metalloid) Ge (germanium – metalloid) Ge (germanium – metalloid) Sn (tin – metal) Sn (tin – metal) Pb (lead – metal) Pb (lead – metal)

Have 4 valence electrons Have 4 valence electrons Carbon, silicon, and germanium share electrons – do not gain or lose electrons Carbon, silicon, and germanium share electrons – do not gain or lose electrons Tin and lead lose 2 or 4 electrons for a +2 or +4 charge. Tin and lead lose 2 or 4 electrons for a +2 or +4 charge.

5.The Nitrogen Family (Group 5A) N (nitrogen – nonmetal) N (nitrogen – nonmetal) P (phosphorus – nonmetal) P (phosphorus – nonmetal) As (arsenic – metalloid) As (arsenic – metalloid) Sb (antimony – metalloid) Sb (antimony – metalloid) Bi (bismuth – metal) Bi (bismuth – metal)

Have 5 valence electrons Have 5 valence electrons GAIN 3 electrons and have a GAIN 3 electrons and have a -3 charge -3 charge

6.The Oxygen Family (Group 6A) O (oxygen – nonmetal) O (oxygen – nonmetal) S (sulfur – nonmetal) S (sulfur – nonmetal) Se (selenium – nonmetal) Se (selenium – nonmetal) Te (tellurium – metalloid) Te (tellurium – metalloid) Po (polonium – metalloid) Po (polonium – metalloid)

Have 6 valence electrons Have 6 valence electrons GAIN 2 electrons to have a GAIN 2 electrons to have a -2 charge -2 charge Also called the chalcogens Also called the chalcogens

7.Halogens (Group 7A) F (fluorine -- nonmetal) F (fluorine -- nonmetal) Cl (chlorine -- nonmetal) Cl (chlorine -- nonmetal) Br (bromine -- nonmetal) Br (bromine -- nonmetal) I (iodine -- nonmetal) I (iodine -- nonmetal) At (astatine – metalloid) At (astatine – metalloid)

Highly reactive -- they are the most reactive nonmetals. Highly reactive -- they are the most reactive nonmetals. Usually combine with most metals to form salts (“Halogen” is Greek for ‘salt former’.) Usually combine with most metals to form salts (“Halogen” is Greek for ‘salt former’.) Have 7 valence electrons Have 7 valence electrons GAIN 1 electron to have a GAIN 1 electron to have a -1 charge -1 charge

8.Noble Gases (Group 8A) He (helium) He (helium) Ne (neon) Ne (neon) Ar (argon) All are nonmetals, Ar (argon) All are nonmetals, Kr (krypton) gases. Kr (krypton) gases. Xe (xenon) Xe (xenon) Rn (radon) Rn (radon)

Have 8 valence electrons Have 8 valence electrons Do NOT react with other elements because they do not need any more electrons to be stable Do NOT react with other elements because they do not need any more electrons to be stable Have a “0” charge Have a “0” charge

C. Transition Metals Found between Gr. 2A and Gr. 3A (“D” block) Found between Gr. 2A and Gr. 3A (“D” block) Valence electrons vary Valence electrons vary They all LOSE electrons They all LOSE electrons Some common transition metals are Some common transition metals are copper, silver, gold, zinc, copper, silver, gold, zinc,

D. Rare Earth Metals or Inner Transition Metals 1. Lanthanoid Series: (also called the Lanthanide series) -- atomic #58 – Lanthanoid Series: (also called the Lanthanide series) -- atomic #58 – 71 They are shiny, reactive metals that are often used to make alloys. They are shiny, reactive metals that are often used to make alloys. 2. Actanoid Series: (also called the Actinide series) -- atomic #90 – Actanoid Series: (also called the Actinide series) -- atomic #90 – 103 Have unstable arrangements or protons and neutrons Have unstable arrangements or protons and neutrons All are radioactive and most are man-made All are radioactive and most are man-made

E. Hydrogen Most common isotope has 1 proton and no neutrons Most common isotope has 1 proton and no neutrons Most common element in the universe Most common element in the universe Behaves like no other element Behaves like no other element Has 1 valence electron Has 1 valence electron Loses the electron to have a Loses the electron to have a +1 charge +1 charge