Chapter 8: Basic Concepts of Chemical Bonding

Question 1

What are the 3 types of chemical bonds?

Answer 1

ionic | covalent | metallic

Question 2

What are ionic bonds?

Answer 2

electrostatic attractions between oppositely charged ions

Question 3

What are covalent bonds?

Answer 3

atoms sharing electrons

Question 4

What are metallic bonds?

Answer 4

electrons are free to move from one atom to another

Question 5

What is the octet rule?

Answer 5

atoms tend to gain/lose/share electrons until they are surrounded by 8 electrons (want to be like noble gas)

Question 6

What does the electron configuration of a noble gas consist of?

Answer 6

FULL s and p orbitals

Question 7

What is the usual pairing of an ionic bond?

Answer 7

a metal from 1A/2A and a nonmetal

Question 8

What does an atom’s ionization energy indicate/affect electron transfer?

Answer 8

indicates how easily an atom can give up an electron

Question 9

What does an atom’s electron affinity effect electron transfer?

Answer 9

measures how much an atom wants to gain an electron

Question 10

What is electron transfer?

Answer 10

when one atom readily gives up an electron (low IE) and the other electron readily accepts an electron (high EA)

Question 11

What are the 3 characteristics of ionic substances?

Answer 11

brittle | high melting point | crystalline

Question 12

What type of process (endothermic or exothermic) is loss of electrons from an atom?

Answer 12

endothermic

Question 13

What type of process (endothermic or exothermic) is gaining of electrons of an atom?

Answer 13

exothermic

Question 14

Why are ionic compounds stable?

Answer 14

attraction between oppositely charged ions draws them closer together = releasing energy (exothermic) = forms a lattice

Question 15

What is lattice energy?

Answer 15

energy needed to completely separate 1mol of a solid ionic compaound into its gaseous ions

Question 16

What describes the stability of a lattice structure?

Answer 16

lattice energy

Question 17

What type of process (endo/exo) is forming ionic compounds?

Answer 17

exothermic

Question 18

What are the 3 things that the lattice energy magnitude of a solid depend on?

Answer 18

charges of the ions (mainly) | ionic size and their arrangement in the solid

Question 19

What is the relationship between lattice energy and the size and radii of the ions?

Answer 19

lattice energy increases as ionic size increases and ionic radii Decreases and distance between ions increase

Question 20

What is the limitation/restriction to adding/removing electrons from s and p elements

Answer 20

s-block: can only remove e- from valence shell | p-block: can only add e- to valence shell = otherwise its energetically unfavorable

Question 21

How are electrons added or removed to/from transition metals?

Answer 21

e- from valence shell are lost first | subsequent removal comes from d-orbital electrons

Question 22

How could atoms have noble-gas electron configurations?

Answer 22

by sharing “borrowing” electrons

Question 23

What is a covalent bond?

Answer 23

chemical bond formed by sharing a pair of electrons

Question 24

How do covalent bonds stick if it is the sharing of electrons?

Answer 24

the shared electrons (any 2 electrons) are in between the atoms’ nuclei, the attractive forces between electron-nucleus “hold” the bond together

Question 25

What are non-bonding pairs in the Lewis Dot Structure?

Answer 25

lone pairs

Question 26

What is bond polarity?

Answer 26

measure of how equally/unequally the electrons in any covalent bond are shared

Question 27

What is a non-polar covalent bond?

Answer 27

electrons are shared equally

Question 28

What is a polar covalent bond?

Answer 28

one of the atoms exerts a greater attraction for the bonding-electrons than the other atom

Question 29

What separates a polar covalent bond from an ionic bond?

Answer 29

difference in magnitude of attraction between an atom for the bonding electrons compared to another atom

Question 30

What is electronegativity?

Answer 30

ability of an atom in a molecule to attract electrons to itself

Question 31

What determines the type of chemical bond in a molecule?

Answer 31

the electronegativity of an atom

Question 32

What 2 things affect an atom's electronegativity?

Answer 32

ionization energy and electron affinity

Question 33

What must the EA and IE of an atom be in order to have an increase in electronegativity?

Answer 33

EA must be (-) and IE increases = resists having its e- taken away

Question 34

Who is Linus Pauling?

Answer 34

developed the first and most widely used electronegativity scale based on thermochemical data

Question 35

What is the periodic TREND for electronegativity?

Answer 35

increases left --> right | increase UPward a group

Question 36

What is the electronegativity in atoms with a non-polar bond?

Answer 36

similar electronegativities

Question 37

What is the electronegativity in atoms with a polar-bond?

Answer 37

one of the atoms is MORE electronegative than the other and the electron density cloud shifts more toward the more electronegative atom

Question 38

What is the electronegativity in atoms with a ionic bond?

Answer 38

difference in electronegativity MUST BE > 2

Question 39

What are polar molecules attracted to and why?

Answer 39

ions, due to their partial charges

Question 40

What is a dipole?

Answer 40

whenever 2 opposite electrical charges are separated by a distance

Question 41

What is a dipole moment (µ)?

Answer 41

quantitative measure of the magnitude of a dipole

Question 42

What are the 3 characteristics of molecular compounds?

Answer 42

low melting point | low boiling point | non-electrolyte behavior in water

Question 43

What is expected when covalent bonding is dominant?

Answer 43

compounds exists as molecules

Question 44

How can we distinguish between an ionic and covalent bond?

Answer 44

use the differences in electronegativity

Question 45

What is a formal charge?

Answer 45

potential charge the atom would have if each bonding e- pain in the molecule were shared equally between 2 atoms

Question 46

What are the 2 ways to identify the dominant Lewis structure?

Answer 46

formal charges are closest to 0 | (-) charges reside on the most electronegative atoms

Question 47

What are resonance structures?

Answer 47

placement of atoms are the same but vary in placement of electrons

Question 48

What bonds do resonance structures only occur with?

Answer 48

double bonds

Question 49

What are the 3 exceptions to the octet rule with molecules and polyatomic ions?

Answer 49

odd # electrons | atom has fewer than 8 valence e- | atom is hypervalent

Question 50

What is hypervalent?

Answer 50

atom has more than 8 valence electrons

Question 51

What are hypervalent molecules formed only for?

Answer 51

central atoms on Period 3 and below due to their large size

Question 52

What is the stability of a molecule related to?

Answer 52

the strength of its covalent bond

Question 53

What happens as the number of bonds between 2 atoms increase to the bond distance, bond enthalpy and bond strength?

Answer 53

shorter distance = atoms closer together = increase in bond enthalpy = increase bond strength