150 likes | 469 Views
Tour of the Periodic Table. The Main Group Elements. Consist of groups 1,2 and 13-18 (everything blue) Electrons are consistent: the elements in each group (column) have the same number of valence electrons. Group 1: Alkali Metals.
E N D
The Main Group Elements • Consist of groups 1,2 and 13-18 (everything blue) • Electrons are consistent: the elements in each group (column) have the same number of valence electrons
Group 1: Alkali Metals • Alkali metals are so named because they are metals that react with water to make alkaline solutions • Have 1 valence electron – that’s 1 electron away from being happy (full shells) so they bond with other elements to get rid of the electron • So highly reactive, they are never found in pure form in nature – always combined with other elements • For example: NaCl (table salt, salt water) • Does not include hydrogen
Group 2: Alkaline-Earth Metals • Second most reactive group of elements in the PT • Named alkaline metals because when in solution, they form basic (or alkaline) solutions with a pH above 7. • Have 2 valence electrons – give up 2 electrons by bonding to become HAPPY and get a full outer shell • Best known: calcium – important mineral in human body
Group 17: Halogens • Halogen – Greek “salt maker” • 7 valence electrons • 1 electron shy of having a full shell – so VERY REACTIVE • Most reactive element in group – fluorine • React with alkali metals to create salts – i.e. NaCl
Group 18: The Noble Gases • Have a full set of electrons in their outermost energy level • UNREACTIVE – stable from full outer shell • Helium used to fill blimps because it is non-flammable, and is lighter than air
Hydrogen: Class of Itself • Most common element in universe • With only 1 electron, hydrogen can react with MANY other elements • Component of organic molecules (us), and is used commercially in production of fertilizer
Metals • Majority of elements are metals • Excellent conductors of electricity (think of wires – what are they made of?) • Excellent conductors of heat (what does a seat belt feel like in a hot car?) • Ductile – can be squeezed into wire • Malleable – can be hammered or rolled into sheets • Solid (except mercury)
Transition Metals • Group 3-12 • DO NOT have identical outer electron configurations • Not very reactive, often found in nature as pure elements • Good conductors of heat and electricity • Ductile and malleable
Nonmetals • Elements to the right of the line are nonmetals • Have properties opposite those of metals • Brittle, non conductors of heat and electricity • Some are liquid
Metalloids • Along staircase border • Cross between metals and nonmetals • Act as semi-conductors – useful in computer chip industry i.e. silicon (Silicon Valley)