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Metals and Nonmetals and Their Ions

1. Properties of Metals and Nonmetals
1. 1.1. Ions of Metals and Nonmetals
2. Practice Problems
3. References
4. Outside Links

At some point in life, you stumble across the words metals and nonmetals, whether in the middle of a conversation about rusty bike fenders or as vocabulary terms in a science textbook in fifth grade, and think to yourself, “metal, like copper, conducts electricity, and nonmetal, like wood, doesn’t.” You might have some general conceptions about metals and nonmetals from personal experience, but there are several more characteristics that contribute to their own uniqueness. On the periodic table, the elements can be divided into two broad categories: metals and nonmetals. There are also subgroups in each category that further accounts for all the properties of the elements.

1. Properties of Metals and Nonmetals
1. 1.1. Ions of Metals and Nonmetals
2. Practice Problems
3. References
4. Outside Links

Properties of Metals and Nonmetals

Metal characteristics include luster, heat and electricity conductivity, malleability (ability to bend instead of crumble), ductility (ability to be shaped or molded), and high melting point. Also, metals are usually reducing agents with lower electronegativities. Metal oxides form a base when they react with water:

Ex: K₂O_(s) + H₂O_(l) ----> 2K⁺_(aq) + 2OH^-_(aq)

(metal oxide) (base)

Nonmetals display dullness, poor heat and electricity conductivity, brittleness (crumble instead of bend), and exist mostly in the liquid or gas form due to lower density and melting points. They are also good oxidizing agents and usually have higher electronegativities. Nonmetal oxides form an acid when they react with water:

Ex: SO₃_(g) + H₂O_(l) ----> H₂SO_{4 (aq)}

(nonmetal oxide) (acid)

The Periodic Table


Subgroup	Definition/Location
Metals
Alkali Metals	series of very reactive metals group 1 on periodic table (with the exception of Hydrogen)
Alkaline Earth Metals	series of reactive metals (less reactive than alkali metals) group 2 on periodic table
Transition Metals	series of elements that exhibit characteristics of metals, though less reactive and less metallic than the first two groups of metals groups 3 - 12 on periodic table
Metalloids - elements that exhibit metallic characteristics as well as some nonmetallic characteristics, such as reactivity (whether as metal or nonmetal) depending on which element it's reacting with ex: Silicon has a metallic luster but is not a good electricity conductor groups 13 - 16, but only the highlighted ones next to stair steps on periodic table
Nonmetals
Halogens	series of elements that are most reactive for nonmetals due to their near-stable electron configuration (a valence shell of 7 electrons) group 17 on periodic table
Noble Gases	series of elements that are inert (nonreactive) due to stable electron configuration (a full valence shell of 8 electrons) group 18 on periodic table

Ions of Metals and Nonmetals

Ions: An atom or group of atoms gain an electric charge by gaining or losing an electron, usually through bonding. Cation: An atom loses electrons and is positive ex: Ca²⁺. Anion: An atom gains electrons and is negative ex: Cl^-.

Metals usually form cations while Nonmetals usually form anions.

All elements on the periodic table (with the exception of noble gases) strive for one of the following more-stable electron configurations:

noble gases' electron configuration with a full valence shell of 8 electrons ex: F ^- = [Ne] 3s² 3p⁶
electron configuration of half-full or full d-orbital in the case of transition metals ex: Ag⁺ = [Kr] 5s¹4d¹⁰5p⁶

Ions of Periodic Groups

Group/Name	Characteristics of Ion
Group 1/Alkali Metals	Noble gas' electron configuration - Loses one electron to have a charge of +1 *Also applies to Hydrogen (H⁺) even though it's not an alkali metal
Group 2/Alkaline Earth Metals	Noble gas' electron configuration - Loses two electrons to have a charge of +2
Groups 3-12/Transition Metals	Electron configuration with half-full or full d-orbital A few transition metals form two ions, and it's best to just know them: Copper (Cu⁺ & Cu²⁺) Iron (Fe²⁺ & Fe³⁺), Mercury (Hg⁺& Hg²⁺), and Tin (Sn²⁺ & Sn⁴⁺) A few transition metals have a specific ion despite the number of valence electrons: Chromium (Cr³⁺), Nickel (Ni²⁺), Silver (Ag⁺), Zinc (Zn²⁺)
Group 13	These elements often choose between losing and gaining electrons to get to noble gas' electron configuration (they can go either way) * Aluminum is an exception: Al³⁺
Group 14	These elements can lose a different number of electrons to achieve stability ex: Sn can lose 2 electrons to get a full s-orbital or 4 electrons to get to noble gas' electron configuration * Lead can only be Pb²⁺
Group 15	Noble gas' electron configuration - gains 3 electrons to have a charge of -3
Group 16	Noble gas' electron configuration - gains 2 electrons to have a charge of -2
Group 17/Halogens	Noble gas' electron configuration - gains 1 electron to have a charge of -1
Group 18/Noble gases	No ion due to existing stable electron configuration of 8 valence-shell electron

Properites of Metals and Nonmetals when they bond

1. Ionic bonds takes place when there's a nonmetal and a metal that exchange electrons.

For Example: Na⁺ + Cl^- = NaCl

Metal + Nonmetal = Ionic

2. Covalent bonds are when electrons are shared between two nonmetals.

For Example: H₂ + 2F^- = 2HF

Nonmetal + Nonmetal = Covalent

In a bond, the charge each element/molecule in a chemical reaction carries over to the element/molecule it is bonding to.

` For Example: Ca²⁺ + 2NO₃^- = Ca(NO₃)₂

The charge of 2+ from the calcium carries over to the NO₃ and the charge of 1- from nitrate carries over to the Ca.

Practice Problems

Apply knowledge about ions to write the following compounds

1) Ca & Cl

Answer: CaCl₂ (Ca²⁺ + 2Cl^-)

2) Fe & S

Answer: Fe(II)S (Fe²⁺+ S^2-)

Apply knowledge about Ions to write oxidation state of the following

1) C₂O₄^2-

Answer: O - O.S. of -2 C - O.S. of +3

(4x -2 charge of O₄ is -8, but this polyatomic ion has an overall charge of -2, which means C₂ has a charge of +6, which gives C a charge of +3) ---> (2_x +3)+(4_x -2) = 6 - 8 = -2, which is overall charge of the ion

2) HCO₃^-

Answer: O - O.S. of -2 H - O.S. of +1 C - O.S. of 4+

(3x -2 charge of O₃ is -6; H has charge of +1 so it becomes -5, but this anion has an overall charge of -1, which gives C a charge of 4+) ---> (1 _x+1)+(1 _x+4)+(3 _x-2) = 1 + 4 - 6 = -1, which is overall charge of the ion

Apply knowledge about oxides to determine whether the product will be an acid or a base

1) MgO + H₂O ---->

Answer: product will be a base because MgO is a metal oxide

MgO + H₂O ----> Mg²⁺ + 2OH^-

2) SO₂ + H₂O ---->

Answer: product will be an acid because SO₂ is a nonmetal oxide

SO₂ + H₂O ----> H₂SO₃

References

Petrucci, Ralph H., William S. Harwood, F. G. Herring, and Jeffry D. Madura. General Chemistry: Principles and Modern Applications. 9th ed. Upper Saddle River: Pearson Education, Inc., 2007.
Brown, Theodore E., Bruce D. Bursten, H. Eugene Lemay. Chemistry: The Central Science. 10th ed. Upper Saddle River: Pearson Education, Inc., 2006.
Metals and Nonmetals, HyperPhysics., <http://hyperphysics.phy-astr.gsu.edu...tab/metal.html>.

Outside Links

Reference for Characteristics of Nonmetals
Reference for Characteristics of Metals
Reference for Characteristics of Metalloids

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Viewing 2 of 2 comments: view all

lebrewster says:

Here's a helpful link for practicing nomenclature
http://misterguch.brinkster.net/pra_namingwkshts.html

Posted 22:34, 20 Nov 2010

lebrewster says:

A video about bonding and knowing the difference between covalent and ionic bonds.
http://www.youtube.com/watch?v=QqjcCvzWwww

Posted 22:55, 20 Nov 2010