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Flashcards in Bonding 2 Deck (30)
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1
Q

Insulators

A

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

2
Q

Semiconductors

A

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

3
Q

Semiconductors

A

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

4
Q

Intrinsic semiconductors

A

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

5
Q

Negative carriers

A

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

6
Q

Positive holes

A

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

7
Q

Extrinsic semiconductor

A

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

8
Q

Doping

A

Process of introducing the impurity

9
Q

N-type semiconductors

A

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

10
Q

N-type conductivity

A

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

11
Q

Acceptor band

A

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

12
Q

P-type conductivity

A

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

13
Q

p-n junctions

A

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

14
Q

p-n junctions function part a

A

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

15
Q

Contact or junction potential

A

The accumulation of charge at p-n junctions

16
Q

Inversely polarized

A

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

17
Q

Directly polarized

A

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

18
Q

Rectifiers

A

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

19
Q

Transistors creation

A

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

20
Q

Transistors

A

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

21
Q

Coordinate covalent bonds

A

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

22
Q

Coordination complexes

A

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

23
Q

Lewis Base

A

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

24
Q

Lewis Acid

A

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

25
Q

Lewis acid base rxn

A

The formation of a coordination complex

26
Q

Ligand(chelator)

A

In coordination chemistry, it is he Lewis Base

27
Q

Crystal lattice

A

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

28
Q

Unit cell

A

The smallest unit that repeats itself indefinitely in three dimensions

29
Q

Lattice energy U

A

The energy of the electrostatic interactions in crystal lattice

30
Q

Crystal

A

Refers to a type of solid