Element Groups and Why They Bond Notes
Luster
Malleable
Alkali Metals
Alkaline Earth Metals
Transition Elements
Lanthanides
Actinides
Name:__________________ Period: ___ Page 1 of 6
Metalloids
Noble Gases
Valence Electrons
Ionic Bonds
Covalent Bonds
Formula Unit
Subscript
Superscript
Chemical Formulas
Polyatomic Ions
Oxidation Numbers
Polar Molecule
Non-polar molecule
Metals: major part of the group
 Most elements are metals.
 88 elements found to the
LEFT of the Zigzag Line
Physical Properties Of Metals
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Luster (shininess)
Good conductors of heat and electricity
High density (heavy for their size)
High melting point
Ductile (drawn out into thin wires)
Malleable (hammered into thin sheets)
Chemical Properties of Metals
 Easily lose electrons (become positive ions CATIONS)
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Corrode easily
 React easily with other elements
ALKALI METALS – GROUP 1, 1A & IA
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Soft metals – they can be cut with a knife
Most reactive of all the metals - React rapidly with oxygen and water
Do not occur in nature in their elemental form
Stored under oil
Will form a +1 ion by giving away their one valence electron
Alkaline Earth Metals Group 2 2A & IIA
 Do not occur in nature in their elemental form
 Will form a +2 ion by giving away their two valence electrons
 Uses
 Fireworks
 Ca – Bones & Teeth
 Ba - X-Rays
Transition Elements Group 3-12
 These elements are most familiar to the public because they are found in nature in their
elemental form
Element Groups and Why They Bond Notes
Name:__________________ Period: ___ Page 2 of 6
 Often form colored compounds
 Chromium precious gems (emeralds and rubies)
 Cadmium yellow
 Cobalt blue
INNER Transition Metals: Lanthanides and Actinides
 Lanthanides
 Elements 58 – 71
 Elements used in motion pictures industry
 Produce colors you see on the TV
 Actinides
 Elements 90 – 103
 All actinides are radioactive and unstable
 Thorium and Uranium are found in the earth’s crust
 Uranium – nuclear reactors
NONMETALS
 Found to the RIGHT of the zigzag line
 Hydrogen is considered a nonmetal
 Group 18 – Noble Gasses are the only group that consists of all nonmetals
 Group 17 - Halogens
 Properties
 Nonmetals gain electrons to become stable – anions
 Most are gasses at room temp
 Not malleable
 Not ductile
 Poor conductors of heat and electricity
 No Luster – Dull
 Important nonmetals in Humans
 Carbon Hydrogen Nitrogen & Oxygen
Metalloids & Synthetic Elements
 Metalloids conduct electricity better than nonmetals, but not as well as metals.
 Synthetic elements do not occur naturally (they are man-made)
 All elements with an atomic number higher than uranium (92) were made by scientists and
most are radioactive.
Electron Dot Diagrams of Selected Elements
 Electron Dot uses the symbol of the element and dots to illustrate the number of electrons in
the outermost energy level
 Elements of the same group (column) have the same number of valence electrons
The Story of Bending the Rules
 Normal atom=
 # Protons= # electrons
Element Groups and Why They Bond Notes
Name:__________________ Period: ___ Page 3 of 6
 Then it’s a neutral atom
 *Remember that all atoms want to have orbital shells be full
 Full shells=
 1st orbital: 2 electrons
 2nd orbital: 8 electrons
Trying to Get Full
 Example: Sodium (Na) has 11 electrons
 (Draw lewis dot diagram here)
 Wants to get rid of 1 valence electron to be full
 Chlorine has 7 valence electrons
 (Draw lewis dot diagram here)
Not Your Normal Atom
 Na now has 10 electrons
 So does Ne
 But not normal Na atom
 Now Na is Na+
 An ion
 Now orbitals are full and atom is electrically charged
 AND ATTRACTIVE to other elements like Cl
Ions
 atom or molecule with missing or extra electrons
 Ions are charged particles (positive or negative)
 charge = #protons - #electrons
 charge given as a trailing superscript
 positive ions are cations X+
 negative ions are anions X–
 Metals= + cations
 Non metals= - anions
Chemical Bonds
 Bonding isn’t just for people.
 Why do atoms form compounds?
 TO BECOME STABLE!!
 What does stable mean to an atom?
 Full set of valence electrons
 Atoms want to have the electron configuration of a noble gas
 Atoms will gain, lose or share electrons in order to obtain a full set of valence
electrons
 Combining Elements
Element Groups and Why They Bond Notes
Name:__________________ Period: ___ Page 4 of 6
 The chemical & physical properties of the elements are different than the properties of the
compound they make up
 Na
+
Cl2
→
NaCl
 Reaction of Sodium with Chlorine & Hydrogen with Oxygen
Types of Bonds
 Ionic Bonds
 Contain a metal & a nonmetal (at least 1 of each)
 Electrons are gained or lost
 Ex. Salt, NaCl
 Covalent Bonds
 Contain 2 or more nonmetals or hydrogen
 Electrons are shared
 Ex. Water, H2O
Ionic Bonding
 In an ionic bond, one atoms gives electrons to another atom.
 When atoms combine this way, it is called a formula unit.
 Ex. NaCl is a formula unit
 The charge of a formula unit is always 0.
 The positive and negative charges must always balance each other.
Formulas
 Chemical Formula—tells what elements a compound contains and the exact number of the
atoms of each element.
 Ex. NaCl has 1 atom of sodium & 1 atom of chlorine
 Ex. H2O has 2 atoms of hydrogen and 1 atom of oxygen.
 A subscript (small # written below) is written after a symbol to tell how many atoms of
that element are in the compound.
Rules for Formulas
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Write the cation (metal) first. Write the anion (nonmetal) second.
The net ionic charge is zero.
Use subscripts to indicate multiple ions.
Write the formula unit in the lowest whole number ratio.
A trick for formula units
 Write both ions with their charges as superscripts. Cu3+ & O2 Crisscross the charges to make the subscripts in the formula
 Do not put + or – in the formula
 Cu3+ & O2Cu2O3
 Silver Chloride
Zinc Phosphide
Aluminum Oxide
Element Groups and Why They Bond Notes
Name:__________________ Period: ___ Page 5 of 6
 IONIC BONDS
 between metals & nonmetals
 Electrons form a give take relationship
 metals give e- (cation)
 nonmetal take e- (anion)
 Held together by attraction of opposite charges
Polyatomic Ions
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Polyatomic Ions=molecule with more then one element that has a charge
The prefix poly- means many in Greek.
Ion consisting of a molecule with many covalently bonded atoms
Act as a single unit
Polyatomic ions is also referred as a radical ion
Name ends in –ate & -ite
-ide usually indicates binary
Multiple Oxidation Numbers
 Some metals (other metals & transition metals) can have more than 1 oxidation number.
 If an element can have more than 1 oxidation number, the charge of the ion is written as a
roman numeral in parentheses.
 Ex. Copper (I) ion is Cu1+
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Copper (II) ion is Cu2+
Mistakes to Avoid
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Roman numerals are not written in the formula
Charges are not written in the formula
Don’t drop polyatomic subscripts
Hydroxide, OH, needs parentheses to indicate multiples.
Cu(II)O
CuO
+1
-1
K Br
KBr
CaNO2
Ca(NO3)2
CaOH2
Ca(OH)2
Rules for Naming
Binary Ionic Compounds with Group A Elements
Write the cation name 1st
 Cation name is the same as the element name
Write the anion name 2nd
 Change the ending of the element name to –ide.
Covalent Bonds
 Covalent bonds share electrons
 Composed of 2 or more nonmetals (and H)
Element Groups and Why They Bond Notes
Name:__________________ Period: ___ Page 6 of 6
 Covalent compounds are called molecules
 Molecules can be polar or nonpolar
 Polar molecule—slightly positive and negative at parts—but overall neutral e- are unevenly
shared
 Nonpolar molecule—electrons are shared equally—completely neutral
Naming Covalent Compounds
 Use prefixes to tell how many of each element you have.
 This is done because you can have different covalent compounds containing the same
elements.
 Change the ending of the 2nd element to -ide
 Ex. N2O is dinitrogen monoxide.
 You can leave off the prefix mono- on the first element.
 Ex. NO2 is nitrogen dioxide
 Not mononitrogen dioxide
Formulas for Covalent Compounds
 Use the prefixes as the subscript in the formula.
 Ex. Phosphorus Trichloride
 PCl3
 Dinitrogen Tetrafluoride
 N 2F 4