2.3 Classifying Elements with the Periodic table

(6.3 pg 157-160)

• The periodic table is very organized – similar elements are grouped together in various ways.

• Elements are listed (left to right) in order of increasing atomic number (# protons)

• Each row (called a period) has the same number of electron shells.

• Each column (called a chemical family) has similar chemical and physical properties.

• Also, the relative position of elements on the periodic table gives us information.

• In the table below and on the LEFT (Fig.1 p.159), metals are blue and on the left side of the table, non-metals are pink and on the right side of the table, metalloids are green and form a ‘zigzag’ line b/w the 2 other classes

Non-Metals

Metals

• The periodic above and on the RIGHT (Fig.2 p.159) shows major chemical families of elements and their group numbers. Some elements don’t share properties with other chemicals, and they don’t have a family (they are in white).

• YOU NEED TO KNOW THE GENERAL CHARACTERISTICS OF THE MAJOR CHEMICAL FAMILIES – SEE TABLE 2 P.158 (it’s good)

• Each square on a detailed periodic table can tell you a lot about the individual element.

• Remember the row gives you the # of e shells. • The relative position from the left end of the table

tells you how many electrons per shell.

• The box itself tells us (Fig 3 p.160):– The symbol & name– The Atomic number = # of electrons/protons that it has.– The Atomic mass = # of protons +neutrons in the

nucleus (average of all isotopes).– Common ion charge(s) = in the upper right hand corner.– MAY contain other info like the boiling point, melting

point, density

• EXTRA TIME YOU SAY??? WELL......• ...let’s take a look at some of the trends associated

with chemical families, and the number of valence electrons in the outer shell....