CEM 141 MSU ACTUAL EXAM #3 2026/2027 WITH MOST TESTED QUESTIONS AND CORRECT DETAILED ANSWERS ALREADY GRADED A

CEM 141 MSU ACTUAL EXAM #3 2026/2027
WITH MOST TESTED QUESTIONS AND
CORRECT DETAILED ANSWERS ALREADY
GRADED A
Polar Bonds
when two atoms of different eleectronegativities bond, the electrons are not shared equally
- results in dipole
Which Bonds are Polar?
H-F
H-O
CH3F
H20
Which Bonds are Not Polar and have similar electrongeativity
H-C
C-C
CF4
CO2
SO3
Triple Bonds
C - sp hybridized
One sigma bond
Two pi bonds
Types of Intermolecular Forces
LDFS
Dipole-dipole interactions
Hydrogen bonds
London Dispersion Forces

, -Present in all substances
-Temporary fluctuating dipoles
-Depends on size, surface area, and shape of molecule
Lewis Dot Structure for H2O
Dipole-dipole Interactions
-Present in polar substances (along with LDF)
-Typically stronger than LDF
Examples: HCL, CH3, CH2O,Ch3OCH3
Hydrogen Bonding Interactions
-Present between two molecules
-H-bonds are extremely strong dipole interactions
Examples: H2O, CH3OH, CH3Ch2OH, HF, NH3


Ionization Energy
energy required to remove an electron from an atom in the gas phase
Left Side Electrons
have weaker attractions to remove electrons
easier to remove electrons from the left side of the table than the right side
Does it take MORE or LESS energy to remove an electron from Li than from Na?
MORE
Why? Because as we move down a group, the orbitals become larger and weaker. While
going across the effective nuclear charge increases. (holds onto the electrons tighter)
Big Bang evidence
universe is expanding (red shift)
Where do atoms come from?
The Big Bang
What were elements formed by?
Nuclear reactions