Elements and their Properties

3 types of elements Metals Nonmetals Mixed groups

Properties of Metal Good conductors of heat & electricity Solid at room temperature Exception: mercury Luster (the ability to reflect light) Malleable (can be hammered or rolled) Ductile (drawn into wires) Ionic & metallic bonding

Alkali Metals Group 1 Softer than most metals Most reactive of all metals React very rapidly with oxygen and water One electron on outer energy level Can be radioactive (emit particles)

Also very reactive, gives up its 2 electrons Alkaline Earth metals Group 2 Also very reactive, gives up its 2 electrons 2 electrons in outer energy level

More stable, often in nature as uncombined elements P. 574 Transition Elements More stable, often in nature as uncombined elements P. 574

Inner Transition Metals Lanthanides: atomic number 58-71 Europium, Gadolinium Actinides: 90-103, radioactive & unstable Uranium

Properties of Nonmetals Nonmetals are elements that usually are gases or brittle solids at room temperature Not malleable or ductile Not good conductors of heat Not shiny

Bonding in Nonmetals Covalent (share electrons) Ionic (gain electrons)

Hydrogen Very reactive Combines with itself and other elements very easily Diatomic molecule: two atoms of the same element in a covalent bond

Halogens Group 17 Very reactive because they just need one more electron!

Noble Gases Last group of the periodic table Exist by themselves They are stable because their outermost energy level is complete

Metalloids Elements that can have properties of both metals & non metals

The most stable number of electrons is to have a complete energy level Ions The most stable number of electrons is to have a complete energy level Metals usually have 1-3 valence electrons The metal is unstable in the state It is going to give up the outer electrons Now, its outermost energy level is full

Ions (cont) Sodium has 11 electrons and 11 protons. The outermost energy level has 1 electron. Sodium loses this electron. Now, Na has 10 electrons and 11 protons Its overall charge is +1 Na+1 or Na+ This is called an ion

Ions (cont) Ion: a charged atom that has either more or fewer electrons than protons.