The Periodic Table Chapter 12 Grouping the Elements

The Periodic Table Chapter 12 Grouping the Elements Section 2

Reminder…

Groups AKA Families • Elements in each family have similar but not identical properties. – For example, lithium (Li), sodium (Na), potassium (K), and other members of family IA are all soft, white, shiny metals. • All elements in a family have the same number of valence electrons. – valence electrons – an electron that is found in the outermost shell of an atom and that determines and atom’s chemical properties

Families of the Periodic Table

Hydrogen • sits on top of Group 1 – BUT it is not a member of that family – Hydrogen is in a class of its own • gas at room temperature • 1 proton, 1 electron, & only 1 energy level • needs 2 electrons to fill up its valence shell

Alkali Metals • Group 1 • have a single electron in their outermost level, in other words, 1 valence electron • shiny • have the consistency of clay • easily cut with a knife

Alkali Metals • most reactive metals • react violently with water • never found as free elements in nature - are always bonded with another element

Alkaline Earth Metals • Group 2 • never found uncombined in nature • 2 valence electrons

Transition Metals • Groups 3 -12 • good conductors of heat and electricity • 1 or 2 valence electrons

Rare Earth Elements • below the Periodic Table • 30 rare earth elements are composed of the lanthanide and actinide series • types of transition metals • lanthanide: shiny, reactive metals • actinide: man-made metals

Boron Family • Group 13 • named after the first element in the family • 3 valence electrons • includes a metalloid (boron), and the rest are metals. • includes the most abundant metal in the earth’s crust (aluminum).

Carbon Family • Group 14 • 4 valence electrons. • includes a non-metal (carbon), metalloids, and metals • carbon is called the “basis of life”

Nitrogen Family • Group 15 • 5 valence electrons • named after the element that makes up 78% of our atmosphere • includes non-metals, metalloids, and metals.

Oxygen Family • Group 16 • 6 valence electrons • share electrons when forming compounds • oxygen is the most abundant element in the earth’s crust

Halogen Family • Group 17 • 7 valence electrons – which explains why they are the most active non-metals • need to gain 1 electron to fill their outermost energy level • never found free in nature • react with alkali metals to form salts

Noble Gases • Group 18 • colorless gases that are extremely un-reactive – inactive because their outermost energy level is full • all the noble gases are found in small amounts in the earth's atmosphere