Minerals—The Building Blocks of Rocks - The Changing Earth: Exploring Geology and Evolution - page 82

Review Questions
1. A pyramid-shaped molecule made up of four oxygen
atoms and one silicon atom is a/an
a. _____ calcium carbonate cube;
b. _____ silica tetrahedron;
c. _____ oxide triangle;
d. _____ sulfi de polygram;
e. _____ ionic bond.
2. An atom with six protons and eight neutrons in its
nucleus has an atomic mass number of
a. _____ 6;
b. _____ 8;
c. _____ 14;
d. _____ 48;
e. _____ 2.
3. The two most abundant elements in Earth's crust are
a. _____ iron and magnesium;
b. _____ potassium and chlorine;
c. _____ aluminum and calcium;
d. _____ oxygen and silicon;
e. _____ carbon and phosphorous.
4. The quality and intensity of light refl ected from a min-
eral is called its
a. _____ density;
b. _____ specifi c gravity;
c. _____ hardness;
d. _____ atomic number;
e. _____ luster.
5. Which one of the following is a common carbonate
rock-forming mineral?
a. _____ calcite;
b. _____ quartz;
c. _____ biotite;
d. _____ muscovite;
e. _____ galena.
6. Minerals that possess the property of cleavage
a. _____ are composed of the noble gases;
b. _____ are noncrystalline solids;
c. _____ break along planes of weakness;
d. _____ are denser than minerals without cleavage;
e. _____ exhibit double refraction.
7. The chemical formula for olivine is (Fe,Mg) 2 SiO 4 ,
which means that
a. _____ silicon and oxygen may or may not be present;
b. _____ ferromagnesian silicates are denser than non-
ferromagnesian silicates;
c. _____ iron and magnesium can substitute for one
another;

d. _____ olivine is a nonferromagnesian silicate;
e. _____ olivine contains iron or magnesium but
never both.
8. Minerals composed of only one chemical element are
known as
a. _____ sulfi des;
b. _____ native elements;
c. _____ phosphates;
d. _____ hydroxides;
e. _____ carbonates.
9. The atomic number of an element is determined by
a. _____ the number of protons in its nucleus;
b. _____ how many electrons it loses during bonding;
c. _____ its color and density;
d. _____ the amount of oxygen present;
e. _____ whether or not it is crystalline.
10. In what type of chemical bonding are electrons shared
by adjacent atoms?
a. _____ octahedral;
b. _____ polymorphic;
c. _____ covalent;
d. _____ ionic;
e. _____ silicate.
11. How are the atomic number and atomic mass number
of an element determined?
12. What is a silica tetrahedron and how may they bond to
form silicate minerals?
13. How do rock-forming minerals differ from any other
mineral? Give examples from three categories of rock-
forming minerals.
14. How do resources and reserves differ? Also, why is
the United States so dependent on imports of some
resources?
15. Give three examples of mineral cleavage and explain
how it occurs. Why do some minerals lack cleavage?
16. What is the distinction between the terms crystalline
and crystal? Where might you fi nd well-formed crystals?
17. What accounts for the fact that some minerals, such as
olivine, have a range of chemical compositions rather
than one specifi c composition?
18. How would the color and density of a rock made up
mostly of ferromagnesian silicates differ from one com-
posed primarily of nonferromagnesian silicates?
19. What are rock-forming minerals and accessory minerals?
20. Briefl y discuss the ways in which minerals form.