Bonding Unit Test Review

Use your notes to answer the following questions.

Name ______Period ______

  1. What are valence electrons? These are the electrons that are the farthest from the nucleus.
  2. The elements in a group have ______The same______number of valence electrons.
  3. Tell the number of valence electrons in each group:

a.Group 11 valence electron

b.Group 22 valence electrons

c.Group 133 valence electrons

d.Group 144 valence electrons

e.Group 155 valence electrons

f.Group 16 6 valence electrons

g.Group 177 valence electrons

h.Group 188 valence electrons

i.Groups 3-12# of valence electrons varies

  1. Cations lose valence electrons and have a ____positive____ ionic charge.
  1. Anions gain valence electrons and have a _____negative___ ionic charge.
  1. How do the electrons behave in a covalent bond?

The valence electrons are shared between atoms.

  1. How do the electrons behave in an ionic bond?

The valence electrons are transferred. Atoms will either gain or lose electrons.

  1. How do the electrons behave in a metallic bond?

Electrons flow freely between atoms.

  1. Which type of bond dissolves easily in water?

Ionic Bonds

  1. Which type of bond has a high melting point? Low melting point?

Ionic bonds and Metallic bonds have high melting points. Covalent bonds have a low melting point.

  1. Which type of bond has the most energy stored in it?

Covalent Bond

  1. Which type of bond conduct electricity as a solution? As a solid?

Ionic bonds conduct electricity as a solution. Metallic bonds conduct electricity as a solid.

  1. Ca(NO3)2

a.Identify the number and kinds of atoms in calcium nitrate.

Ca =1 atomN=2 atomsO =6 atoms

b.What type of bond is found in calcium nitrate?

Ionic bond

Ca2+ ion combined with NO3-

  1. Write the name of the following compounds:

a.Fe(NO3)3 ______Iron (III) Nitrate______

b.N2O5 ______Dinitrogen Pentoxide______

c.Ca(OH)2______Calcium Hydroxide______

d.CoCl2 ______Cobalt (II) Chloride______

e.SnBr4 ______Tin (IV) Bromide______

f.CO ______Carbon Dioxide______

g.Al2(SO4)3 ______Aluminum Sulfate______

  1. Write the formulas of the following compounds:

a)lithium chloride ______LiCl______

b)calcium nitrate ______Ca(NO3)2______

c)iron (II) sulfate ______FeSO4______

d)phosphorus pentabromide ____PBr5______

e)sodium fluoride ______NaF______

f)copper (II) carbonate____CuCO3______

g)calcium nitrate ______CaNO3______

  1. How do the properties of a compound compare to the properties of the elements that make up that compound?

The properties of a compound are DIFFERERENT than the properties of the elements that make it up.

  1. How do the Properties of compounds made from the same elements, but in different ratios, compare? The properties are DIFFERERENT in compounds that are made of the same element but in different ratios. Ex. water (H2O) and hydrogen peroxide (H2O2)
  2. Can you predict the properties of a compound based on the properties of the elements that it is composed of?

No, the properties of a compound are DIFFERERENT than the properties of the elements that make it up.

  1. What are the characteristics of a metallic bond?
  • Metal + Metal

•In metals, valence electrons are shared, free to move about.

•Good conductors of heat and electricity in all states.

•Malleable solid

•Strong bond, but weakest of the three bond types.

•High melting point and boiling point.

•Insoluble in H2O.

•Insoluble in nonpolar solvents.

•Lustrous

  1. What are the characteristics of an ionic bond?
  • Metal + Nonmetal
  • One atom gains, one loses electrons.
  • Strong Bond but not as strong as a covalent bond.
  • Crystalline solid.
  • brittle
  • Very high melting point.
  • Soluble in H2O.
  • Insoluble in nonpolar solvents.
  • Nonconductor of heat and electricity in solid form.
  • Conducts electricity in aqueous solutions or when melted.
  1. What are the characteristics of a covalent bond?
  • Nonmetal + Nonmetal
  • Formed by sharing electron pairs
  • Strongest bond type
  • Gas, liquid, or a soft solid at room temperature.
  • Low melting point and low boiling point.
  • Most are Insoluble in H2O
  • Soluble in nonpolar solvents.
  • Nonconductor of heat and electricity.
  • Nonlustrous
  1. Name the type of bond that results from each:

a.Metal + Metal = ______Metallic Bond______

b.Nonmetal + Nonmetal = _Covalent Bond______

c.Metal + Nonmetal = _____Ionic Bond______

  1. What is electronegativity?

Electronegativity is the ability of an atom to attract electrons.

  1. How does electronegativity affect a chemical bond?
  1. Differentiate between an element, compound, molecule, and mixture (both homogeneous and heterogeneous)
  • An element is made from one type of atom.
  • A compound is two or more different atoms bonded together. Must be at least two different elements.
  • A molecule is two or more atoms bonded together whether it is the same element or different elements.
  • A mixture contains two or more pure substances (elements and compounds) and has variable composition. The substances are not bonded and they retain their chemical properties.
  • A homogeneous mixtureis a substance in which two or more substances are uniformly spread out.
  • A heterogeneous mixture is a mixture that contains substances that are not evenly mixed.
  1. What causes a compound to be polar?

A polar molecule is an unequal sharing of electrons that result in a slight negative charge on one side of the molecule and a slight positive charge on the opposite side of the molecule.

  1. What is an intermolecular force? An intermolecular force is a force of attraction between different molecules rather than bonding forces within the same molecule.
  2. Describe the following:

a.Hydrogen BondBonding between hydrogen and more electronegative neighboring atoms such as oxygen and nitrogen. IT IS NOT A BOND.

b.Dipole –Dipole forceAttractive forces between polar molecules

c.Ion-Dipole forceAttractive forces between an ion and a polar molecule

d.London Forcesmomentary dipoles occurring due to uneven electron distributions in neighboring molecules as they approach one another

  1. Describe the properties of water.
  • Formula = H2O
  • High specific heat
  • State at Room Temperature = Liquid
  • Melting Point = 0 oC
  • Boiling Point = 100 oC
  • Less Dense as a solid
  • High surface tension
  • Capillary action
  • Essential to all living organisms
  1. What is capillary action?

Capillary action results from the adhesive force between the molecules of liquid and the side of the tube. This is how water moves through plants.

  1. What is surface tension?

Surface tension is the tendency of liquids to keep a low surface area. It creates a “skin” on the surface of the liquid. Water has a high surface tension.

  1. What property of water makes it a universal solvent?

Water molecules are polar which allows for it to dissolve many compounds and makes it the universal solvent.

  1. Why is water essential to all living organisms?
  • It is a major component in cells
  • Water has many useful biological roles such as:
  • being a solvent
  • a coolant
  • an insulator
  • as support
  • a lubricant
  • a reagent.
  • Water is used
  • in chemical reactions
  • for transporting
  • providing a suitable environment
  1. Diagram the following molecules. Tell the shape of the molecules, the type of bond in each molecule, and if the molecule is polar or nonpolar. Show the polarity of the bonds using this symbol

a.Water H2O

b.Methane CH4

c.Ammonia NH3