It's your choice.

After reading the feature articles in this issue--"The Plight of the Turtle," "Surf vs. Sand," and "Sandcastle Physics"--choose the correct answer to each question.

1 People harvest turtle eggs
mainly as a
A. decorative object.
B. way to raise leatherbacks.
C. method to monitor turtle
   development.
D. food source.

2 A leatherback's diet
consists mainly of
A. shrimp.
B. plankton.
C. jellyfish.
D. sharks.

3 The tiny bumps on a
leatherback's shell
A. break surface tension in
   swimming.
B. insulate from cold water.
C. protect against predators.
D. ease movement on land.

4 Which of the following
statements about the
leatherback is not true?
A. Its life span can exceed
   50 years.
B. It's one of four endangered
   sea turtle species.
C. A female can produce 75
   eggs per clutch.
D. It can swim 60 kilometers
   a day.

5 Niche identity is a
term ecologists use
to define how
A. organisms develop?
B. organisms are classified
   taxonomically.
C. species fit into the
   ecosystem.
D. turtles recognize their
   nesting grounds.

6 Which of the following can
explain why Galapagos
tortoises are endangered?
A. Goats were introduced
   to the islands, competing
   for food.
B. Lonesome George
   cannot mate.
C. Whales and seals devoured
   too many tortoises.
D. Cloning tortoises is
   premature.

7 Some U.S. beaches are
washing away because
A. erosion is not working.
B. too many surfers ride
   the waves.
C. littoral drift batters the
   coastline.
D. wave action and currents
   carry sand away.

8 Which of the following is not
true? Waves are formed and
shaped by
A. storms thousands of miles
   away from shore.
B. wind blowing on the
   surface of the water.
C. beach nourishment
   projects.
D. features on the ocean
   floor.

9 A wave breaks when
A. speed increases.
B. height increases.
C. it topples over.
D. it stops moving.

10 Which of the following
is not a solution to beach
erosion?
A. artificial sand
B. beach nourishment
C. geotubes
D. jetties

11 Sand is composed of
A. sulfur dioxide and calcium
   carbonate.
B. silicon dioxide and
   calcium carbonate.
C. silicon dioxide and
   calcium chloride.
D. sodium chloride and
   calcium carbonate.

12 Why does water make sand
stick together?
A. Water is smaller than
   sand grains.
B. Water has surface tension.
C. Water exerts a compacting
   force.
D. Water is stronger than
   gravity.

TAKE IT FURTHER

1. Research a marine animal endangered by commercial fishing. What is being done to protect the species?

2. Some sandy beaches are white, while others are gray or black. Research what causes the differences in color.

1.d 2.c 3.a 4.b 5.c 6.a 7.d 8.c 9.c 10.a 11.b 12.b

IT'S YOUR CHOICE Test your chemistry IQ! Answer the following questions about elements and the periodic table.

1. Name the mystery
element!

--

2. Group elements
share similar chemical
properties. In
pure form, the mystery
element has the
same crystal structure
as a diamond.
Which of the following
elements most
likely composes this
gem?

A Magnesium (Mg)
B Carbon (C)
C Gallium (Ga)
D Bromine (Br)

3. Metalloids share
properties with
nonmetals and metals.
Which of the
following is not a
metalloid?

A Tin (Sn)
B Boron (B)
C Astatine (At)
D Arsenic (As)

4. Which elements
below are arranged
by size, from smallest
to largest?

A Pt, Au, Ag, Cu
B Fe, Co, Mn, Cr
C Ne, Mg, Ca, Sr
D P, As, N, Bi

5. Which element
has 51 neutrons in
its nucleus?

A Cerium (Ce)
B Sulfur (S)
C Zirconium (Zr)
D Francium (Fr)

B. Which statement
about metals is not
true?

A They're located on the
  left of the periodic table.
B Tantalum is a metal.
C They're excellent
  conductors of heat and
  electricity.
D No metals are naturally
  liquid.

HOT ROCK: The mystery element's pure form has a gray metallic luster and a melting point of 1,410[degrees]C (2,570[degrees]F).