General Properties of Nonmetals

Properties of nonmetals are more varied than those of metals. Hydrogen, oxygen, nitrogen, fluorine, chlorine, and the noble gases are all gases in the elemental state, whereas only bromine is a liquid. All the remaining nonmetals are solids at room temperature. Unlike metals, nonmetals are poor conductors of heat and electricity, and when they form compounds, nonmetals can exhibit either positive or negative oxidation numbers. 

A small group of elements, called metalloids, have propenies characteristic of both metals and nonmetals. The metalloids boron, silicon, germanium, and arsenic are semiconducting elements (see Section 20.3). 

Remember that the halogens also form anions that ate isoelectronic with the noble gases [Mt Section 7.5], 

Hydrogen is the simplest element known—its most common atomic form contains only one proton and one electron. The atomic form of hydrogen exists only at very high temperatures, however. Normally, elemental hydrogen is a diatomic molecule, the product of an exothermic reaction between H atoms  

Molecular hydrogen is a colorless, odorless, and nonpoisonous gas. At 1 atm. liquid hydrogen has a boiling point of -252.9°C (20.3 K). 

In a compound containing a metal and a nonmetal, the nonmetal is an anion. The anionic charge of a nonmetal is predictable from the position of the non-metal on the periodic table. You begin on the far right and count towards the left until you get to the column containing the nonmetal of interest. The noble 

A Even though fluorine only exists in compounds in the —1 oxidation state, it, like all elements, has a zero oxidation state in the elemental form. This means that fluorine is —1 in CaF2, PbF2, SF4, and CIF3, and 0 in F2. 

A nonmetal may adopt any oxidation number between the values predicted in the preceding two paragraphs. The only exceptions are fluorine, which is only -1 in compounds, and helium, neon, and argon, which have no known compounds. When there is a choice of oxidation states, there must be additional information available in order to allow you to choose the correct state. 

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There are some exceptions to the general properties of nonmetals. For example, carbon can conduct electricity, although it has all other nonmetal properties. Bromine is a liquid at normal temperatures, and it is the only liquid non-metal. All of the elements that are gases at normal temperatures are nonmetals. All of the metals, on the other hand, are solids at normal temperatures except for mercury, which is a liquid. (The element gallium melts at 91-93°F [31-32°C], which is just above room temperature.)... 

QUESTIONS AND PROBLEMS GENERAL PROPERTIES OF NONMETALS Review Questions... 

As an important introductory tool, the reader should note the following general properties of nonmetals ... 

Table 2.4. General Properties of the Corrosion Resistance of Nonmetals to Various Chemicals [11]...

The general properties of metals and nonmetals are distinct. Physical and chemical properties that distinguish metals from nonmetals are summarized in Tables 4-3 and 4-4. Not all metals and nonmetals possess all these properties, but they share most of them to varying degrees. The physical properties of metals can be explained on the basis of metallic bonding in solids (Section 13-17). 

Describe the general properties of metals and nonmetals and understand how trends in metallic behavior relate to ion formation, oxide acidity, and magnetic behavior understand the relation between atomic and ionic size and write ion electron configurations ( 8.5) (SPs 8.6-8.8) (EPs 8.47-8.65)... 

Nonmetals are not as easy to recognize as metals because they do not always share physical properties. However, in general the properties of nonmetals are the opposite of metals. They are not shiny, are brittle, and are not good conductors of heat and electricity. 

Nonmetallic. Formed generally by the combination of nonmetals and having the characteristic properties of nonmetals. 

This chapter starts by examining the general properties of the nonmetals. (21.1)... 

Describe general properties of metals, nonmetals, and metalloids. 

As a general rule, metalloids tend to have the physical characteristics of metals and the chemical properties of nonmetals. 

In aqueous geochemistry, the important distinguishing property of metals is that, in general, they have a positive oxidation state (donate electrons to form cations in solution), but nonmetals have a negative oxidation state (receive electrons to form anions in solution). In reality, there is no clear dividing line between metals and nonmetals. For example, arsenic, which is classified as a nonmetal, behaves like a metal in its commonest valence states and is commonly listed as such. Other nonmetals, such as selenium, behave more like nonmetals. 

The most obvious correlation of the electronegativity scale with the general chemical properties of the elements bears on their division into metals and nonmetals. It is seen that the value x = 2 represents ap-... 

The modern periodic table provides us with volumes of information about the elements. Metals are on the left side of the table, nonmetals are on the right side, and metalloids divide these two groups. In general, metals are shiny, malleable, ductile, and conduct electricity. Nonmetals are dull, brittle, and do not conduct electricity (many nonmetals are gases at room temperature). Metalloids have properties of both metals and nonmetals. 

In Chapter 4 we learned that the known elements can generally be divided into two classes, metals and nonmetals. On the periodic table, the elements are arranged by increasing atomic number in rows and columns. As these rows and columns are generated, the elements with metallic properties fall on the left side of the table, and the elements without metallic properties fall on the right side of the table. In Activity 6.1, we will examine the physical and chemical properties of metals to understand why they are so often the material of choice in jewelry making. 

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