Which of the following is the symbol for an alkali metal?

Which of the following is the symbol for an alkali metal?
 a. Al
  b. Cl
  c. K
  d. Ca

---

[Ques. 2] Earth's oceanic crust ranges in thickness from about
 a. 98 to 140 km.
  b. 5 to 11 km.
  c. 19 to 98 km.
  d. 18 to 26 km.

---

[Ques. 3] The Group 7A element astatine (85At) would be predicted to occur in what phase?
 a. Liquid
  b. Solid
  c. Plasma
  d. Gas

---

[Ques. 4] Earth's continental crust ranges in thickness from about
 a. 98 to 140 km.
  b. 19 to 40 km.
  c. 5 to 26 km.
  d. 8 to 16 km.

---

[Ques. 5] Which element is used in safety flares and fireworks because it burns so brightly?
 a. Potassium
  b. Magnesium
  c. Carbon
  d. Chlorine

---

[Ques. 6] Earth's thin, rocky, outer layer on which we live is called the
 a. seismosphere.
  b. geosphere.
  c. asthenosphere.
  d. crust.

---

[Ques. 7] Calcium carbonate is the major component of each of the following except
 a. limestone.
  b. seashells.
  c. stalagmites.
  d. bones.

---

[Ques. 8] The structural region of Earth that has the greatest volume is the
 a. crust.
  b. outer core.
  c. mantle.
  d. inner core.

---

[Ques. 9] Hydrogen is generally classified as a
 a. semimetal.
  b. nonmetal.
  c. metal.
  d. noble gas.

---

[Ques. 10] The structural region of Earth that is a viscous liquid is the
 a. mantle.
  b. outer core.
  c. inner core.
  d. lithosphere.