Introduction to the Periodic Table
When organized according to atomic num- ber in a table, elements with similar proper- ties occupy the same column and are called a group or family.
On the periodic table, the properties of the elements change gradually across a horizontal row called a period.
The periodic table can be divided into representative elements and transition elements.
The groups on the periodic table are known also by other names. For instance, Group 17 is known as halogens.
Atoms of elements in Groups 1 and 2 readily combine with atoms of other elements.
Each element in Group 2 combines less readily than its neighbor in Group 1. Each alkaline earth metal is denser and has a higher melting point than the alkali metal in its period.
Sodium, potassium, magnesium, and cal- cium have important biological roles.
The metals in the iron triad are found in a variety of places. Iron is found in blood and in the structure of skyscrapers.
Copper, silver, and gold are fairly unreac- tive, malleable elements.
The lanthanides are naturally occurring ele- ments with similar properties.
The actinides are radioactive elements. All actinides except thorium, proactinium, and uranium are synthetic.
Copy and complete the following concept map on the periodic table.
CHAPTER STUDY GUIDE K ◆
(l)Yoav Levy/PhotoTake NYC/PictureQuest, (r)Louvre, Paris/Bridgeman Art Library, London/New York