7.6 Metals, Nonmetals, and Metalloids

By: Monique Briones, Marie Leibfreid, Bryanne Vollmer, Richard Wang

In the Periodic Table

• No elements exist naturally as individual atoms EXCEPT noble gases

• Metals—left and middle

• Nonmetals—top right• Metalloids—between

metals and nonmetals

• Hydrogen nonmetal

Increase

Increase

Characteristic PropertiesMetals

• Luster, various colors (silver)• Solids malleable and ductile• Good conductors heat and

electricity• Oxides are basic ionic solids• Form cations aqueous solution• Corrode• Dense • High melting point

Nonmetals• No luster, various colors• Solids brittle, hard and soft• Poor conductors heat and

electricity• Oxides molecular substances form

acidic solutions• Anions or oxyanions in aqueous

solution• Cannot change shape without

breaking• Low melting point

• Metallic Character—the extent to which an element exhibits the physical and chemical properties of metals

• Nonmetallic Character— “the extent…” nonmetals

Metals• Solids room temp. (except

Hg, Cs 28.4C, Ga 29.8C)• Low ionization energies• Oxidized• Form positive ions easily• Noble Gas Electron

Configuration (Alkali 1+, Alkaline Earth 2+)

• Transition metals more than one positive ion

• Alkali, Alkaline Earth, Transition, and Other

Metals Cont.

• Compounds with nonmetals are ionic (Ex: oxides)

• Metal oxides basic, dissolve in water to form metal hydroxides (due to oxide ion)

• React with acids to form salt and water

• High melting point

Alkali

• Group 1A• Reactive• Do not occur naturally

on their own• Bond with other

elements since there is only one e- in outer shell

• Soft• Explode in water

Alkaline Earth

• Oxidation number: +2• Reactive• Not naturally found

uncombined in nature• I.E.– Beryllium– Calcium– Radium

Transition

• Groups 3-12• Valence e- in more than

shell• Several oxidation states• I.E.– Titanium– Iron– Cobalt

Other Metals• Groups 13-15• Solid• High density• Opaque (light cannot get

through)• Oxidation numbers:

+3,+/- 4, -3• I.E.

– Aluminum– Tin– Lead

Metal Chemical Reactions

• Metal + Nonmetal ––––> Ionic substance– Ex: 2Ni(s) + O2(g) ––––> 2NiO(s)

• Metal Oxide + Water ––––> Metal Hydroxide– Ex: Na2O(s) + H20(l) ––––> 2NaOH(aq)

– Ex: CaO(s) + H20(l) ––––> Ca(OH) 2(aq)

• Basicity Due to Oxide Ion– Ex: O2-

(aq) + H2O(l) ––––> 2OH-(aq)

• Metal Oxide + Acid ––––> Salt + Water– Ex: NiO(s)+ 2HCl(aq)––––> NiCl2 (aq) + H2O(l)

Nonmetals• Vary greatly in appearance• 7 Diatomic (Gas: H2, N2, O2, F2,

Cl2; Liquid: Br2; Solid: I2)• Gain electrons when react

with metals to form noble gas electron configuration

• Completely nonmetal compounds are molecular substances

• Oxides acidic, dissolve in water to form acids (acid rain)

• Dissolve in basic solution to form salts

Nonmetal Chemical Reactions

• Tend to gain electrons when react with metals– Ex: 2Al(s) + 3Br2(l) ––––> 2AlBr3(s)

• Nonmetal Oxide + Water ––––> Acid– Ex: CO2(g) + H2O(l) ––––> H2CO3(aq)

– Ex: P4O10(s) + 6H2O(l) ––––> 4H3PO4(aq)

• Nonmetal Oxide + Base ––––> Salt + Water– Ex: CO2 (g) + 2NaOH(aq) ––––> Na2CO3(aq)+ H20(l)

Metalloids• Have metal and nonmetal

properties• Found in stair shaped section of

periodic table• Used in computers & calculators• Shiny or dull depending on

element• Shape can be changed easily• Ex: Silicon

– Looks like metal– Brittle– Poorer conductor of heat and

electricity than metal• Electrical semiconductors

Additional Research

Chemical BehaviorMetals

• Reducing Agents• Form oxides that react with

water to give hydroxides• Form basic hydroxides• React with O, F, H, and other

nonmetals, giving ionic compounds

• React with other metals, giving metallic compounds

• Lower electronegativities• Have 1-5 electrons in valence,

usually not more than 3• Low ionization potentials,

form cations by loss of electrons

Nonmetals• Oxidizing agents (except noble

gases)• Form oxides that react with

water to give acids• Form acidic hydroxides• React with O, F, H, and other

nonmetals, giving covalent compounds

• React with metals, giving ionic compounds

• Higher electronegativities• Usually have 4-8 electrons in

valence• High electron affinities, form

anions by accepting electrons in valence (except noble gases)

Physical BehaviorMetals

• Good conductors of heat and electricity

• Malleable and ductile in solid state

• Metallic luster• Opaque• High density• Mostly solids• Crystal structure in which

each atom surrounded by 8-12 nearest neighbors (metallic bonds between atoms)

Nonmetals• Poor conductors• Brittle and nonductile in solid

state• Show no metallic luster• May be transparent or

translucent• Low density• Gases, liquids, or solids• Form molecules that consist

of atoms covalently bonded; noble gases monatomic

Metalloids• Has both properties• Has appearance of metal, but

behaves chemically like nonmetal

• Boron (B), Silicon (Si), Germanium (Ge), Arsenic (As), Antimony (Sb), Tellurium (Te), Polonium (Po), Astatine (At)

• Not Aluminum• Semiconductors of electricity• Conductivity increases with

temp. (metals decrease)• Ex: Silicon

– Metallic luster– Forms weak acid

Periodic Trends• Consistent with trends of

ionization energy, electron affinity, and electronegativity

• Effective nuclear charge increase across period (left to right) and decrease down group (top to bottom)

• Atomic Radius (decrease)• Ionization Energy (increase)• Electron affinity (general

increase)• Electronegativity (increase)• Polarizability (Decrease)

Dependence Oxidation Number

• As oxidation number of element increases, metallic behavior decreases, nonmetallic behavior increases

• HOCl (+1) is weak acid, HClO4 (+7) is strong acid

• TlCl (+1) is ionic,TlCl3 (+3) is covalent

Acidic and Basic Properties

• MgO(s)+ 2HCl(aq) ––––> MgCl2 (aq) + H2O(l)

• CO2 (g) + NaOH(aq) ––––> NaHCO3(aq)

• Al2O3(s) + 6HCl(aq) ––––> 2AlCl3(aq) + 3H20(l)

• Al2O3(s) + 2NaOH(aq) ––––> 2Na[Al(OH)4](aq)

• Basic oxide—oxide that reacts with acids• Acidic oxide—oxide that reacts with bases• Amphoteric oxide—oxide with both basic and acidic

properties

Helpful Websites:

• http://www.gordonengland.co.uk/elements/non%20metals.htm

• http://www.cstephenmurray.com/onlinequizes/chemistry/readingperiodictable/metalnonmetal.htm ***

• http://www.mikeblaber.org/oldwine/chm1045/notes/Periodic/Metals/Period06.htm

• http://www.webelements.com/