Quick Review SPI Periodic Table Periodic table  A chart of all known chemical elements  Shows all the different types of atoms Purpose  To quickly locate a variety of information about a particular element How is it organized  Organized into rows called periods  Organized into columns called groups (also called families)  Arranged in numerical order (by the atomic number)  Also arranged other ways (metals, nonmetals, metalloids, etc) PRESS THE RIGHT-ARROW BUTTON ON YOUR KEYBOARD TO ADVANCE THROUGH THE PRESENTATION

 Columns are called groups Notes SPI Periodic Table  Groups are also called families  Group 1 is called the alkali metal family (see below) Group 1=Alkali Metals Groups/Families Alkali Metals:  Notice they are in group 1.  So they have one valence electron.  Their outer shells are not full.  Easily react with other elements. Why? Alkali metals are the most reactive group/family!

Notes SPI Periodic Table  Group 2 is called the alkali-earth metal family (see below) Group 2=Alkali-Earth Metals Groups/Families Alkali-Earth Metals:  Notice they are in group 2.  So they have two valence electrons.  Their outer shells are not full.  Easily react with other elements. Why? Alkali-earth metals are very reactive!

Notes SPI Periodic Table  Groups 3 to 12 are called the transition metals (see below) Groups 3 to 12=Transition Metals Transition Metals Transition Metals (Lanthanides) Transition Metals (Actinides) Groups/Families

Notes SPI Periodic Table  Group 17 is called the halogen family (see below) Group 17=Halogens Groups/Families Halogens:  Notice they are in group 17.  So they have seven valence electrons.  Their outer shells are not full.  Easily react with other elements. Why? Halogens are very reactive! (Flourine is the most reactive non-metal)

Notes SPI Periodic Table  Group 18 is called the noble gas family (see below) Group 18=Noble Gases Groups/Families Noble Gases:  Notice they are in group 18.  So they have 8 valence electrons.  Their outer shells are completely full.  They do not react with other elements. Why? Noble gases are non-reactive!

 Valence electrons are the key. (These are the electrons in the outermost energy level.)  The number of valence electrons determines how and if the element/atom will chemically react/bond Reactivity in Elements Notes x 5 x Boron Atom Note: Boron has three total valence electrons +

Electrons are located in shells according to rules: 1)The 1st shell can hold up to two electrons 2) Other outer shells can hold up to 8 electrons. CLE Chemical Bonding Reactivity in Elements Notes

… elements/atoms react to fill their outer electron shells Chemical Reactions/Chemical Bonding: 2 Key Types of Chemical Bonds 1) Ionic bonds are… 2) Covalent bonds are… CLE Chemical Bonding … the transfer of electrons … the sharing of electrons Notes Reactivity in Elements

IONIC BOND bond formed by electron transfer

Notes COVALENT BOND bond formed by sharing of electrons