Chapter 4-3 Warm - Up 1. How are periods and groups organized in the periodic table? 2. What is the difference between an anion and cation? 3. What is the atomic mass, # of protons, neutrons, and electrons in Boron? 4. What is an isotope?
Chapter 4-3 Atoms and the Periodic Table Families of Elements
Three Groups of Elements 1st Group: Metals – Shiny and conducts heat and electricity
Three Groups of Elements 2nd Group: Nonmetals – Elements that don’t conduct heat or electricity
Three Groups of Elements 3rd Group: Semiconductors – Element or compound that conducts heat and electricity but not as well as a metal
Properties of Metals Conductor - heat and electricity Solid at room temperature (except Mercury Hg). Luster – Reflect light Malleable - hammered / rolled into sheets. Ductile - drawn into wires
Alkali Metals
Alkali Metals
Alkali Metals Most reactive Softer than other metals Don’t occur in nature Salt NaCl 1 electron in its outer energy level (Group 1)
Alkaline Earth Metals
Alkaline Earth Metals
Alkaline Earth Metals 2 electrons in its outer energy level (Group 2) Magnesium – fireworks, ladders, planes, bats Calcium – strong bones Radium – treats cancer
Transition Elements
Transition Elements Group 3 -12 Less reactive Found as free metals Commonly found in nature
Synthetic Elements Man Made Radioactive – Nuclei decaying Elements greater than 92 Used in medicine, smoke detectors, and weapons
Nonmetals Oxygen, nitrogen, and sulfur Plentiful on Earth Found on right side of table
Halogens
Halogens Group 17 Very reactive Seven valence electrons – 1 to complete
Uses of Halogens Chlorine compounds are used to disinfect water Bromine compounds are used as dyes in cosmetics Iodine – hormone production When heated, iodine changes directly to a purple vapor (sublimation)
Noble Gases
Noble Gases Un-reactive - outermost energy levels are full Exists as a single atom instead of a molecule Group 18
Noble Gases Group 18 Helium - light weight makes it useful in hot air balloons Neon and argon - used in “neon lights” for advertising
Semiconductors 6 elements Semiconductors - Can conduct electricity better than most nonmetals, but not as well as some metals Silicon – used in computer chips