MSU CEM 141 Final Question and Answer
| Grade A+ | 2026/2027 Latest Study
Guide
• Dalton's Atomic Theory -✓✓1) Elements are composed of atoms.
2) Atoms of same element are identical, and have the same mass and properties.
3) Atoms of a given element are different from atoms of other elements.
4) Compounds are formed by combinations of atoms of two or more elements.
5) Chemical reactions are due to the rearrangements of atoms, atoms (matter) are
neither created nor destroyed during a reaction.
• Cathode Ray Tube -✓✓Glass tube consisting of 2 electrodes under very low pressure.
When a high voltage is applied, cathode emits "particles" that move toward anode.
• Thomson's Experiments showed -✓✓1. Particles emerge from one disc and move to
the other
2. Particles could be deflected by electrical fields or magnetic fields
3. Particles carried the electrical charge
• Number of electrons = -✓✓Number of protons
• 4 Known fundamental forces are -✓✓Gravity, Electromagnetic, Strong Nuclear Force,
and Weak Nuclear Force.
• The electromagnetic force is mediated by the -✓✓Electric and Magnetic Fields
• Electromagnetic force > -✓✓Gravity
• Coulomb's law represents -✓✓The force between charges
• What is Energy? -✓✓We don't know but changes in energy are caused by changes in
forces.
• System -✓✓Part of the universe you are looking at
• Surroundings -✓✓Everything else in the universe
• Kinetic Energy is energy associated with -✓✓Motion.
• Potential Energy -✓✓1. Energy associated with the position of system of objects in a
field.
2. Must be 2 or more objects
, 3. Must be a field.
• How many atoms must be present for LDFs to exist? -✓✓2 or more.
• As atoms approach each other... -✓✓Potential energy decreases
• When atoms overlap -✓✓Potential energy increases
• What happens when you add thermal energy to the He atoms? -✓✓1. Kinetic energy
increases, they move faster, they collide and vibrate with more energy.
2. Once they vibrate to a certain point they fly apart
• Thermal Energy is -✓✓A measure of the average kinetic energy of the atoms.
• Temperature is -✓✓Directly related to average kinetic energy.
• What happens when you break an interaction between atoms? -✓✓Energy is
absorbed into the system.
• LDFs -✓✓1. Increase with size of a particle (# of e-)
2. Increase with surface area
3. Temporary Fluctuating Dipoles
4. FOR NONPOLAR MOLECULES IT'S THE ONLY IMF
5. Present in all substances in the solid and liquid states
• Electrons were discovered by who? -✓✓JJ Thompson
• Electrons were discovered before -✓✓Neutrons and protons
• What is the evidence from Thomson's experiment that all atoms contain electrons? -
✓✓The particles were identical regardless of the identity of the cathode.
• Alpha Particle has -✓✓2 protons and 2 neutrons
• Rutherford's Model was called -✓✓The Planetary Model/ Nuclear Model
• Thomson's Model was called -✓✓Plum pudding model
• Neutrons were discovered by -✓✓James Chadwick
• Neutrons are -✓✓1. In nucleus
2. Slightly heavier than protons
3. Harder to detect (neutral charge)
| Grade A+ | 2026/2027 Latest Study
Guide
• Dalton's Atomic Theory -✓✓1) Elements are composed of atoms.
2) Atoms of same element are identical, and have the same mass and properties.
3) Atoms of a given element are different from atoms of other elements.
4) Compounds are formed by combinations of atoms of two or more elements.
5) Chemical reactions are due to the rearrangements of atoms, atoms (matter) are
neither created nor destroyed during a reaction.
• Cathode Ray Tube -✓✓Glass tube consisting of 2 electrodes under very low pressure.
When a high voltage is applied, cathode emits "particles" that move toward anode.
• Thomson's Experiments showed -✓✓1. Particles emerge from one disc and move to
the other
2. Particles could be deflected by electrical fields or magnetic fields
3. Particles carried the electrical charge
• Number of electrons = -✓✓Number of protons
• 4 Known fundamental forces are -✓✓Gravity, Electromagnetic, Strong Nuclear Force,
and Weak Nuclear Force.
• The electromagnetic force is mediated by the -✓✓Electric and Magnetic Fields
• Electromagnetic force > -✓✓Gravity
• Coulomb's law represents -✓✓The force between charges
• What is Energy? -✓✓We don't know but changes in energy are caused by changes in
forces.
• System -✓✓Part of the universe you are looking at
• Surroundings -✓✓Everything else in the universe
• Kinetic Energy is energy associated with -✓✓Motion.
• Potential Energy -✓✓1. Energy associated with the position of system of objects in a
field.
2. Must be 2 or more objects
, 3. Must be a field.
• How many atoms must be present for LDFs to exist? -✓✓2 or more.
• As atoms approach each other... -✓✓Potential energy decreases
• When atoms overlap -✓✓Potential energy increases
• What happens when you add thermal energy to the He atoms? -✓✓1. Kinetic energy
increases, they move faster, they collide and vibrate with more energy.
2. Once they vibrate to a certain point they fly apart
• Thermal Energy is -✓✓A measure of the average kinetic energy of the atoms.
• Temperature is -✓✓Directly related to average kinetic energy.
• What happens when you break an interaction between atoms? -✓✓Energy is
absorbed into the system.
• LDFs -✓✓1. Increase with size of a particle (# of e-)
2. Increase with surface area
3. Temporary Fluctuating Dipoles
4. FOR NONPOLAR MOLECULES IT'S THE ONLY IMF
5. Present in all substances in the solid and liquid states
• Electrons were discovered by who? -✓✓JJ Thompson
• Electrons were discovered before -✓✓Neutrons and protons
• What is the evidence from Thomson's experiment that all atoms contain electrons? -
✓✓The particles were identical regardless of the identity of the cathode.
• Alpha Particle has -✓✓2 protons and 2 neutrons
• Rutherford's Model was called -✓✓The Planetary Model/ Nuclear Model
• Thomson's Model was called -✓✓Plum pudding model
• Neutrons were discovered by -✓✓James Chadwick
• Neutrons are -✓✓1. In nucleus
2. Slightly heavier than protons
3. Harder to detect (neutral charge)
