Question

how are nonmetals different from metals? recall that metals have luster. they are ductile, malleable, and good conductors of electricity and thermal energy. all metals except mercury are solids at room temperature. the properties of nonmetals are different from those of metals. nonmetals do not conduct electricity or thermal energy well. those that are solid at room temperature have no luster. many of the nonmetals are gases at room temperature. nonmetals in groups 14–16 look at the periodic table in this chapter or in the back of this book. notice that groups 14–16 contain metals, nonmetals, and metalloids. the chemical properties of the elements in each group are similar. however, the physical properties of the elements can be different. nonmetals in the groups include carbon, nitrogen, phosphorus, oxygen, sulfur, and selenium. group 17: the halogens group 17 of the periodic table is above and to the right. an element in group 17 of the periodic table is called a halogen (hal juhn). halogens can react with a metal and form a salt. for example, chlorine gas reacts with solid sodium and forms sodium chloride, or table salt. all halogens react readily with other elements and form compounds. in fact, they can occur naturally only in compounds. they do not exist as free elements. group 18: the noble gases group 18 of the periodic table is shown at right. the elements in group 18 are known as the noble gases. the elements helium, neon, argon, krypton, xenon, and radon are the noble gases. unlike the halogens, the only way noble gases react with other elements is under special conditions in a laboratory. they do not form compounds naturally. key concept check 2. identify what properties do nonmetals have? __________ ________ ________ foldables make a chart with three columns and three rows to organize information about nonmetals and metalloids. reading check 3. predict will bromine (br) react with sodium? explain your answer. ________ ________ __________ visual check 4. identify label each figure on the left with the correct group number from the periodic table.

Explanation:

Key Concept Check 2

From the text, nonmetals' properties are: Poor conductors of electricity/thermal energy; solid nonmetals (at room temp) have no luster; many are gases at room temp; (also, from context, unlike metals, they aren't ductile/malleable, and most nonmetals (except some) have different states/conductivity).

Halogens (Group 17) react readily with metals (like sodium) to form salts (e.g., chlorine + sodium → sodium chloride). Bromine is a halogen (Group 17), so it should react with sodium because halogens react with metals to form salts, and bromine, as a halogen, has this reactive property (reacts readily with other elements, especially metals, to form compounds).

Using the text: Group 17 = Halogens (F, Cl, Br, I, At); Group 18 = Noble Gases (He, Ne, Ar, Kr, Xe, Rn); Groups 14 (C, Si, etc.), 15 (N, P, etc.), 16 (O, S, etc.) have nonmetals. Match the figures to these groups.

Answer:

Nonmetals are poor conductors of electricity and thermal energy. Solid nonmetals (at room temperature) have no luster. Many nonmetals are gases at room temperature. They are not ductile or malleable (unlike metals).

Reading Check 3