Bonding 2

Question 1

Insulators

Answer 1

A solid in which electrons saturate a band and a considerable gap exists between the completely filled band and the next available one

Question 2

Semiconductors

Answer 2

Electrical properties intermediate between metals and insulators; in semiconductors the forbidden energy gap is relatively small and can be overcome by thermal means of a moderate electrical field

Question 3

Semiconductors

Answer 3

Unlike metals, semiconductors are substances with electrical conductivities that increase with increasing temperature

Question 4

Intrinsic semiconductors

Answer 4

A solid in which the band gap is so small that some electrons from the VB will occupy energy levels in the CB

Question 5

Negative carriers

Answer 5

Electrons in the upper level resulting from the slight electron population in the conduction band

Question 6

Positive holes

Answer 6

Results when the slight electron population in the conduction band causes these to form in the lower level

Question 7

Extrinsic semiconductor

Answer 7

A substance that is normally an insulator but if small amounts of atoms are introduced into the lattice become semiconducting

Question 8

Doping

Answer 8

Process of introducing the impurity

Question 9

N-type semiconductors

Answer 9

Formed when a doping atom possesses more external electrons than the parent atom.

Question 10

N-type conductivity

Answer 10

The donor band is close to the conduction band, and the thermal excitation of electrons from the donor band to the empty conduction band enables a current to flow; charge carriers are negative electrons

Question 11

Acceptor band

Answer 11

Created when the impurity has less external electrons than the parent atom and lies close to and above the filled silicon valence band

Question 12

P-type conductivity

Answer 12

The charge carriers are positive holes; the process in the valence band can also be seen as a hole moving across a row of atoms, in the direction opposite to the flow of electrons

Question 13

p-n junctions

Answer 13

Consist are f s p-type semiconductor that’s in close contact with an n-type semiconductor

Question 14

p-n junctions function part a

Answer 14

A few electrons of the n-zone migrate spontaneously toward the p-type zone; the migration confers a - charge to the p-zone and a + charge to the n-zone

Question 15

Contact or junction potential

Answer 15

The accumulation of charge at p-n junctions

Question 16

Inversely polarized

Answer 16

When the junction offers a resistance to the current flow; no current can flow through the system; happens if p-zone is connected to the negative pole and the n-zone the positive pole of a battery

Question 17

Directly polarized

Answer 17

Current can flow freely; happens when p-zone is connected to the positive energy pole and n-zone the negative pole; flow of e- occurs in the normal direction

Question 18

Rectifiers

Answer 18

P-n junctions allows the current to flow only in the direction of direct polarization so an AC is turned into a DC

Question 19

Transistors creation

Answer 19

Made by insetting a p-type semiconductor between two n-type semiconductors; creating 2 interfaces and attaching the (+) & (-) poles so that one applied potential increases the supply of carriers to another potential

Question 20

Transistors

Answer 20

Acts as an amplifier, when a n-p-n transistor is inserted b/w 2 circuits where I can then take the current in one circuit and produce a proportional current in the other one at a higher potential

Question 21

Coordinate covalent bonds

Answer 21

When covalent bonds form b/w a transition metal and a polar molecule like water or ammonia

Question 22

Coordination complexes

Answer 22

Molecules that consist of a transistor metal ion bonded to polar molecules via a coordinate covalent bond; H3B-NH3

Question 23

Lewis Base

Answer 23

A molecule that donates a pair of electrons to form a covalent bond

Question 24

Lewis Acid

Answer 24

A molecule that accepts a pair of electrons to form a covalent bond

Question 25

Lewis acid base rxn

Answer 25

The formation of a coordination complex

Question 26

Ligand(chelator)

Answer 26

In coordination chemistry, it is he Lewis Base

Question 27

Crystal lattice

Answer 27

Ions in an ionic compound that are arranged in a regular pattern that repeats itself regularly; crystal = type of solid

Question 28

Unit cell

Answer 28

The smallest unit that repeats itself indefinitely in three dimensions

Question 29

Lattice energy U

Answer 29

The energy of the electrostatic interactions in crystal lattice

Question 30

Crystal

Answer 30

Refers to a type of solid