Chapter 21 Test

Question 1

Which of the following elements cannot be used in p-doping:

Answer 1

P

Question 2

What is generally needed in the reduction step for processing metals?

Answer 2

High temperature

Question 3

The mineral galena is an ore for which metal?

Answer 3

lead

Question 4

Which of the following is refined using an electrolytic cell?

Answer 4

copper

Question 5

Which of the following represents the reduction step in processing?

Answer 5

ZnO + C → Zn + CO

Question 6

Which metal is obtained from the ore bauxite?

Answer 6

Aluminum

Question 7

In semiconductors, the energy gap is _____

Answer 7

between the conduction band and the valence band

Question 8

Which of the following elements is the most resistive at room temperature?

Answer 8

Si

Question 9

Which statement best describe what a p-type semiconductor is?

Answer 9

A p-type semiconductor conducts electricity by movement of positively charged holes.

Question 10

Aluminum is:

Answer 10

the most common metal in the lithosphere

Question 11

An alkali metal, M, reacts with water. Which would be the balanced equation?

Answer 11

2M(s) + 2H2O(l) <==> 2M+(aq) + 2OH-(aq) + H2(g)

Question 12

Which of the following substances does not contain calcium?

Answer 12

Epsom Salts

Question 13

Although aluminum is a strong reducing agent, aluminum cans do not “rust”. Why?

Answer 13

Aluminum oxide creates a protective coating.

Question 14

Why is metal a good conductor of heat?

Answer 14

The electrons gain kinetic energy and pass it quickly to other electrons.

Question 15

How are the alkali metals generally isolated?

Answer 15

Reduction of the chloride salt by chemical or electrical means

Question 16

Which of the following aluminum ores contains aluminum and no other metals?

Answer 16

Corundum

Question 17

Which of the following is the most abundant metal in the lithosphere?

Answer 17

Aluminum

Question 18

Which would not have been a use of aluminum prior to 1886?

Answer 18

Cookware such as pots and pans

Question 19

If the two different types of semiconductors are “sandwiched” together, the resulting electrical junction is known as a p-n junction. What can a p-n junction be used as?

Answer 19

A diode

Question 20

Suppose a layer of n-type semiconductor is between two layers of p-type semiconductor materials forming a p-n-p device. What is this device called?

Answer 20

Transistor

Question 21

How does the free electron model explain electrical conductivity?

Answer 21

Delocalized electrons are easily passed between metal ions.

Question 22

What is a semiconductor?

Answer 22

A substance that sometimes conducts electricity.

Question 23

A semiconductor is able to conduct a current:

Answer 23

in both the conduction band and the valence band

Question 24

Which of the following compounds cannot exist?

Answer 24

Na(OH)2

Question 25

Potassium metal is purified by reduction with sodium metal rather than through electrolysis like the other alkali metals

Answer 25

true