Chapter 2: Atomic Structure and Interatomic Bonding

Question 1

Mass of Electrons:

Answer 1

9.11 x 10 ^-31 kg

Question 2

Mass of Protons / Neutrons

Answer 2

1.67 x 10 ^ - 27 kg

Question 3

Atomic Number

Answer 3

Protons in nucleus of atom = # of electrons in neutral species

Question 4

Atomic Mass Unit (AMU)

Answer 4

1 / 12 the mass of 12C

Question 5

Atomic Weight

Answer 5

Wt of 6.022 x 10 ^23 molecules of atoms

1 amu / atom = 1 g / mol

Question 6

Electron Behavior

Answer 6

Wave-like / particle-like characteristics

Probability of electron’s being at various locations around the nucleus

Question 7

Energy States

Answer 7

Electrons have discrete energy states

Tend to occupy the lowest available energy state

Question 8

Electron configuration in most elements

Answer 8

Not stable; Valence (outer) shell usually not filled completely

Question 9

Quantum Numbers

Answer 9

Characterization of electrons in an atom through 4 parameters

Question 10

4 Parameters of Quantum Numbers

Answer 10

Principle Quantum Number (n)

Angular momentum ( I)

Magnetic (m)

Spin (s)

Question 11

Principle Number (n)

Answer 11

Distance from nucleus

Question 12

Angular Momentum (I)

Answer 12

Shape of Orbital

Question 13

Magnetic (m)

Answer 13

Orientation in space

Question 14

Spin (s)

Answer 14

Electron Spin

Question 15

Pauli Exclusion Principle

Answer 15

Each energy level can only hold no more than two electrons of opposite spin

Question 16

Ionic Bond

Answer 16

Metal + Nonmetal

Metal donates electrons, while nonmetal accepts electrons

Requires electron transfer

Question 17

Energy in Ionic Bonding:

Answer 17

Minimum energy is the most stable.

Balance of attractive and repulsive terms

Question 18

Net Energy for Ionic Bonding Formula (En)

Answer 18

Ea + Er = (- A / r) + (B / r^n)

Ea: Attractive energy
Er: Repulsive Energy
r: Interatomic separation

Question 19

Covalent Bonding

Answer 19

Similar electronegativity

Share electrons

Bonds determined by valence - S & p orbitals

Question 20

Primary Bonding

Answer 20

Metallic Bond

Ionic-Covalent Mixed Bonding

Question 21

% Ionic Character

Answer 21

(1 - e ^ -((xa - Xb)^2/4) x 100%

Xa and Xb are Pauling electronegatives

Question 22

Secondary Bonding

Answer 22

Interaction between dipoles

Permanent dipoles molecule induced

Question 23

Details of Ionic Bonds

Answer 23

Large bond energy

Nondirectional

Ceramics

Question 24

Details of Covelent Bonding

Answer 24

Variable Bond Energy

Directional

Semiconductors, ceramics, polymer chains

Question 25

Details of Metallic Bonding

Answer 25

Variable Bond Energy

Nondirectional

Question 26

Secondary Bonding

Answer 26

Smallest Bond Energy

Directional

Inter-chain

Inter-molecular