MSU CEM 141 FINAL STUDY GUIDE
EXAM QUESTIONS AND ANSWERS
Scientific Questions can be answered by... - --Doing experiments
-Making observations
-Taking measurements
- Atomic number= - -Number of protons
- 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
EXAM QUESTIONS AND ANSWERS
Scientific Questions can be answered by... - --Doing experiments
-Making observations
-Taking measurements
- Atomic number= - -Number of protons
- 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
