Non-Metals: Properties & Uses PDF

## 3.5 Nonmetals In the periodic system there are also non-metals. Various non-metals are found in nature, which are quite useful. ### Properties of non-metals: * there are three physical entities * the surface of some non-metals in the solid state is not as smooth as that of metals * some solid...

## 3.5 Nonmetals In the periodic system there are also non-metals. Various non-metals are found in nature, which are quite useful. ### Properties of non-metals: * there are three physical entities * the surface of some non-metals in the solid state is not as smooth as that of metals * some solid non-metals are crumbly * they do not shine, i.e. they do not reflect light * most do not conduct electrical current (this is important, because they can be used to produce covers for electrical cables) * many non-metals do not conduct heat * have low melting and boiling points * they are not strong and do not emit sound like metals * some of the non-metals are in a gaseous state ### Uses of Non-metals: * **Sulfur:** is used to vulcanize tires, making them stronger. * **Oxygen:** In hospitals, pure oxygen is used to help patients who have trouble breathing. * **Helium:** Balloons and balloons are filled with helium. * **Chlorine:** Aqueous chlorine solution is used to kill bacteria. ### Additional Nonmetal Examples * **Carbon:** is used to purify water. * **Silicon:** is used to make computer chips. ### Questions and Assignments 1. Write the names of five nonmetals except sulfur and helium. 2. Why is sulfur used? 3. Why is helium used for filling balloons? Argue the argument. ### Activity 3.5 - Research on non-metals: - Look at the periodic table. Choose one of the nonmetals. Use knowledge and information obtained from the Internet to describe it. - Use the following questions to get information about: - Why are non-metals used? - What are their properties? - Where are they found in nature? - Should non-metals be processed before they are used? If so, how is this process carried out? - Do you know any special facts about non-metals? - Present your results in the form of a report or prepare a poster with them. ### Briefing * Solid nonmetals have low melting and melting points. * They are breakable. * Some non-metals are in a gaseous state. * They do not conduct heat or electric current.