Which of the following is NOT a property of a metal?
Solid at standard temperature
Which of the following is not a refining method?
Distilling
Which of the following represents the reduction step in processing?
ZnO + C → Zn + CO
Which of the following is not an alloy?
iron
Which of the following is a property of a metal?
conduct electricity
Which of the following shows the electron configuration for di-lithium in a gas state?
2s ____↑↓_____
Which of the following electron configuration would be an electrical conductor?
[Cu] 4s13d10
Which of the following electron diagrams shows lithium?
2s ____↑_____
What type of solid is diamond?
Network
Germanium is used in nuclear physics as a radiation detector. The energy gap in germanium is 0.72 eV. Suppose a 600-keV photon passes through a germanium crystal, gradually losing all of its energy by exciting electrons to the conduction band. About how many electrons will be moved to the conduction band?
8.3 × 10^5 electrons
Which one of the following has the largest energy gap between the valence band and the conduction band?
An insulator
What happens to the conductivity of a semiconductor as the temperature increases?
It increases.
Which of the following results in a p-type semiconductor?
Si doped with Al
Which of the following mixtures is least likely to have the characteristics of a semiconductor?
ZnO
As the temperature of a metal is increased, the conductivity decreases because molecular orbitals are perturbed by the vibrational energy of the atoms. Which of the following describes what happens to the conductivity of semiconductors with increasing temperature?
The conductivity increases but then decreases at even higher temperatures
Which of the following results in an n-type semiconductor?
Ge doped with As
What is the most common oxidation state for alkali metals?
+1
Which of the following elements is an alkali metal?
Lithium, Li
Which two alkali metals are essential elements in living organisms?
Sodium and potassium
What is the third most common element in seawater?
Magnesium
Arrange the steps of the Dow process of magnesium isolation in the correct order:
- Mg(OH)2 + HCl -> MgCl2 + 2H2O
- Mg2+ + 2OH- -> Mg(OH)2
- CaO + H2O -> Ca(OH)2
- MgCl2(l) -> Mg(s) + Cl2(g)
3, 2, 1, 4
Which of the following equations correctly describes the water softening process?
Ca2+(aq) + 2HCO3- (aq) + Ca2+(aq) + 2OH-(aq) -> 2CaCO3(s) + 2H2O(l)
Which of the following aluminum ores contains aluminum and no other metals?
Corundum
Arrange the steps of the Bayer process of alumina production (from bauxite) in the correct order:
- Al(OH)4- -> Al(OH)3 + OH-
- Al(OH)3 + OH- -> Al(OH)4-; Al(O)OH + OH- + H2O -> Al(OH)4-
- Al(OH)3 (heated) -> Al2O3 + H2O
- AlCl3 + 3K(Hg)x(l) -> 3KCl(s) + Al(Hg)x(l)
2, 1, 3
All of the following compounds are amphoteric except:
CaO