Chemistry
Name_____________________________________
Date__________ Block____
Unit 7: Chemical Bonding
As a result of activities in Chemistry, you should be able to:
1. Use the periodic table to identify metals and nonmetals.
2. State the general properties of metals and nonmetals with respect to gaining or
losing valence electrons during a chemical reaction.
3. Distinguish between cations [cat-eye-ons](positive ions) and anions [an-eye-ons](negative
ions).
4. Using the periodic table and knowledge of electron configurations, state the number
of valence electrons for a given representative element.
5. Define electronegativity as the tendency of an atom to attract electrons to itself
when it is combined with other atoms.
6. Interpret a table of electronegativity values to determine whether a given element will
gain or lose valence electrons during a chemical reaction.
7. Define:
a) ionic bond: the electromagnetic attraction between oppositely charged ions or
between two atoms having a difference in electronegativity  1.8.
(metal ion + nonmetal ion)
b) covalent bond: the chemical bond that results from the mutual (but not
necessarily equal) sharing of one or more pairs of electrons by two atoms having
a difference in electronegativity  1.8. (2 or more nonmetals)
(1) single covalent bond: involves the sharing of one pair of electrons
(2) double covalent bond: involves the sharing of two pairs of electrons
(3) triple covalent bond: involves the sharing of three pairs of electrons
(4) nonpolar covalent bond: covalent bond between two atoms having a
difference in electronegativity that is  0.5. (share electrons equally)
(5) polar covalent bond: covalent bond between two atoms having a
difference in electronegativity that is  0.5 but  1.8.
(unequal sharing of electrons
8. Use absolute differences in electronegativity to predict the type of bond that would
form between two atoms.
9. Draw Lewis dot structures to represent neutral atoms, ions, formula units of ionic
compounds, and molecules. Distinguish between polar and nonpolar molecules
and basic VSEPR shapes (linear, bent, tetrahedral, and trigonal pyramidal)
Objectives continue on other side.
10. Draw representations of molecular compounds involving single, double, and/or
triple covalent bonds.
11. State the general physical properties of ionic and molecular substances and explain
those properties with respect to the types of chemical bonds involved.
12. Define hydrogen bonding as the relatively strong intermolecular forces by which
a hydrogen atom that is covalently bonded to a very electronegative atom is ALSO
weakly bonded to an UNSHARED electron pair of a strongly electronegative atom
(e.g., N, O, S, P) in the same molecules or in a nearby molecule:
O  H ……… O  H


H
H
13. Identify the properties of water that result from hydrogen bonding and the
phenomena that demonstrate these properties, including:
a) density (solid ice is less dense than liquid water)
b) high heat of vaporization (such a small molecule would be expected to
require much less heat energy to change from a liquid to a gas)
c) high boiling point (such a small molecule would be expected to have a much
lower boiling point; in fact, it would be expected to be a gas at room
temperature)
d) high specific heat (such a small molecule would be expected to require
much less heat energy to increase the temperature of 1.0 g of water by 1.0 oC).
e) hydration of ionic compounds (because of the polarity of the water
molecule, the more negative region around the oxygen atom tends to
associate with positively charged ions dissolved in the water, while the more
positive regions around the hydrogen atoms tend to associate with negatively
charged ions dissolved in the water; these associations result in water
molecules surrounding individual ions)
f) high surface tension (at the interface between the liquid water and the
air, the hydrogen bonding between adjacent water molecules results in a
membrane-like surface of the water; this surface tension results in the
formation of water drops, allows you to “overfill” a glass, and allows some
species of insects to literally “walk on water”)
14. State the significance of water to life on Earth (as a solvent, a fluid medium
(oceans, etc.) and as a reactant and/or product in photosynthesis, cellular
respiration, and other biochemical reactions.
15. Describe the chemical properties of acids and bases:
a) acids
1) react with active metals to produce hydrogen gas)
2) react with carbonates and bicarbonates to produce carbon dioxide gas
3) turn blue litmus paper red
4) taste sour
5) have a pH less than 7.0
6) are corrosive (chemically deterioriates and wears away a substance)
b) bases
1) react with fats to produce soaps (saponification)
2) turns red litmus blue
3) taste bitter
4) have a pH greater than 7.0
5) are caustic (“burns” living tissue – reacts with the fats/oils in cells)
16. Identify acids and bases from their chemical formulas: inorganic acids contain hydrogen as
the first element in the formula; most bases contain hydroxide as the negative ion in the
formula.
17. State the names and chemical formulas for common acids and bases:
HCl(aq)
hydrochloric acid
NaOH(aq)
sodium hydroxide(aq)
HC2H3O3(aq) acetic acid
KOH(aq)
potassium hydroxide(aq)
HNO3(aq)
nitric acid
Mg(OH)2(aq) magnesium hydroxide(aq)
H2CO3(aq)
carbonic acid
Ca(OH)2(aq) calcium hydroxide(aq)
H2SO4(aq)
sulfuric acid
Ba(OH)2(aq) barium hydroxide(aq)
H3PO4(aq)
phosphoric acid
NH3(g)
ammonia gas: NH3(g) does not
dissolve in H2O(l), the NH3(g) chemically
reacts with H2O(l) to form NH4OH(aq)
18. Define: strong acid, strong base, weak acid, weak base; give at least one
example of each:
strong acids and strong bases dissociate completely in aqueous solutions;
weak acids and weak bases dissociate only partly in aqueous solutions.
Strong acids: HCl, H2SO4, HNO3; weak acids: HC2H3O2, H2CO3, H3PO4, HCN
Strong bases: NaOH, KOH, Ba(OH)2; weak base: NH3
19. Interpret a pH scale and correctly use a variety of indicators to determine the pH of a
solution.