422-004+chapter+1+summaries

//Section 3: Elements//
 * Chapter 1: Matter and Change**

The periodic table is a table of elements is organized into three major categories metals, nonmetals, and metalloids. The groups or families are the vertical columns that contain elements with the same or nearly same chemical properties. The horizontal row is called the periods. Their physical and chemical properties change a little bit as you go across the rows. Lanthanide and actinide are the groups of elements placed underneath the table of elements.

The periodic table is divided into two main groups the metals and nonmetals. Metals are good conductors of both heat and electricity. Some properties of metals are that they are ductile, tensile to strength, has a sliver or grayish white luster, and they are malleable. Metals are recognized by their shininess and metallic luster. Copper doesn’t change in pure, dry air, but it does when it is heated. It is an important mineral in a human’s diet.

Nonmetals are not good conductors of heat and electricity. They are mainly gases, but there is one liquid and a few solids. Phosphorus is a solid nonmetal that has two forms: red phosphorus which is a dark red powder and white phosphorus which is a waxy solid. Phosphorus is too reactive to be in nature. This element exists in all living things.

Metalloids have elements of both metals and nonmetals. They are solid, but less malleable than metals, but not so much as breakable as nonmetals. They are semiconductors of electricity, just because they are a cross between metals and nonmetals.

Noble gases are the elements that tend to be not so much reactive. Since they are low reaction they make them different from the other elements. The elements in this group include neon, argon, krypton, xenon, and helium. Helium is used in balloons and all the rest of the elements are used in lights.