Chapter 4

Question 1

When a main group element forms a cation

Answer 1

,it tends to lose all its valence
electrons

Question 2

When a transition metal forms a cation

Answer 2

it tends to lose its outermost s
electrons first, then sometimes lose one or two additional d electrons
from the next-to-outermost shell.

Question 3

The bond length is determined by

Answer 3

the distance at which the lowest potential energy is achieved

Question 4

Breaking a chemical bond

Answer 4

takes energy (endothermic process)

Question 5

Forming a chemical bond

Answer 5

releases energy (exothermic process)

Question 6

A pure covalent bond is

Answer 6

a covalent bond are identical (diatomic)

Question 7

A polar covalent bond is

Answer 7

when one atom has a partial negative charge and the other has a partial positive charge

Question 8

Electronegativity is

Answer 8

how much an atom “wants” electrons.

Question 9

In a polar bond, the more electronegative atom

Answer 9

pulls the electrons closer, creating a positive (δ+) and a negative (δ-) charge on the atoms.

Question 10

The greater the difference
in electronegativity

Answer 10

The more polar it is

Question 11

Electronegativity

Answer 11

increase across a period, and a
decrease down a group

Question 12

Electron Affinity

Answer 12

measures the energy change when an electron is added to an atom

Question 13

The lattice energy (∆Hlattice ) of an ionic compound
is

Answer 13

a measure of the strength of the attraction between its positive and negative ions

Question 14

Exceptions to the octet rule:
1. Odd-electron molecules

Answer 14

only get each atoms as close
as possible to a full octet

Question 15

Exceptions to the octet rule:
2. Electron-deficient molecules (the central atom doesn’t have an octet)

Answer 15

a central atom from group 2 or 13

Question 16

Exceptions to the octet rule:
3. Hypervalent molecules (the central atom has more than an octet)

Answer 16

from period 3 and higher,

Question 17

Formal charge =

Answer 17

valence electrons – # lone pair electrons – ½ # bonding electrons

Question 18

The shorter the bond..

Answer 18

The stronger it is

Question 19

Bond energy

Answer 19

decreases down a group
increases across a period (left to right)
increases with the number of bonds

Question 20

Bond length

Answer 20

increases down a group
decreases across a period (left to right)
decreases with the number of bonds

Question 21

Bond length Exception:

Answer 21

H-F is longer than
H-H, but stronger

Question 22

Enthalpy change

Answer 22

Δ𝐻 = bonds broken-bonds formed

Question 23

Electron-pair geometry

Answer 23

includes all electron pairs
(lone pairs and/or bonds)

Question 24

Molecular structure

Answer 24

Only includes bonds and
atoms (no lone pairs)

Question 25

lone pair-lone pair lone pair-bonding pair bonding pair-bonding pair

Answer 25

most repulsion second most less repulsion

Question 26

lone pair triple bond double bond single bond

Answer 26

most space second most third most least space

Question 27

Polar covalent bonds connect two atoms with differing electronegativities is called

Answer 27

bond dipole moment

Question 28

A bond dipole moment is

Answer 28

represented with an arrow pointing towards the more EN atom.

Question 29

f the overall dipole moment is zero, the molecule is.. If the overall dipole moment is non-zero, the molecule is...

Answer 29

non-polar. polar.

Question 30

he strength of a covalent bond depends on

Answer 30

the extent of overlap of the orbitals involved.

Question 31

A sigma bond (σ bond) is

Answer 31

a covalent bond where the electron density is focused along the axis that connects the nuclei of the two atoms.

Question 32

A pi bond (π bond) is

Answer 32

a type of covalent bond formed when two p orbitals overlap side by side. The overlap happens on either side of the line connecting the two nuclei, and there is no electron density along that line.

Question 33

which bond is stronger

Answer 33

π bonds are generally weaker than σ bonds for the same pair of atoms, because they have less orbital overlap

Question 34

sp hybridization

Answer 34

LINEAR This process took one s orbital and one p orbital to form two sp orbitals An sp orbital has 50% s character, and 50% p character

Question 35

sp2 hybridization

Answer 35

TRIGONAL PLANAR This process took one s orbital and two p orbitals to form three sp2 orbitals An sp2 orbital has 33% s character, and 66% p character

Question 36

sp3 hybridization

Answer 36

TETRAHEDRAL This process took one s orbital and three p orbitals to form four sp3 orbitals An sp3 orbital has 25% s character, and 75% p character

Question 37

Hybrid orbitals overlap to form Unhybridized orbitals overlap to form

Answer 37

σ bonds. π bonds.