MSU CEM 141 FINAL EXAM QUESTIONS AND
ANSWERS VERIFIED 100% CORRECT
Dalton's atomic theory (1800s) - ANSWER --elements composed of small,
indivisible, indestructible, particles (atoms)
-all atoms of each element are identical (mass/properties)
-no subatomic particles
-compounds are formed by combos of atoms from 2+ elements
-chemical reactions occur from rearrangement of atoms
What increases the number of electrons to be emitted by the photoelectric effect? -
ANSWER -Intensity.
JJ Thomson - ANSWER --first person to provide evidence of electron
-cathode ray tube
-plum pudding model
-particles carried electric charge
A particle that transfers light energy with a definable energy, emits one electron
energy of = h (6.626 x 10^-34 J) - ANSWER -Photon.
cathode ray tube - ANSWER --JJ Thomson
-electron particles were emitted from cathodes
-particles carried electric charge
-ray was independent of the element it came from
-particles identical regardless of cathode
-proved all atoms contained electrons
Energy of light equation? - ANSWER -E = hV.
plum pudding model - ANSWER --atoms contained electrons embedded in the
middle
-JJ Thomson
,h - ANSWER -Planck's constant, the energy of a photon.
alpha particle - ANSWER -2 neutrons, 2 protons
What happens to the energy when there is a short wavelength? - ANSWER -High
energy.
Light from the sun (white light) can be separated by a prism to create this, only a
small part of the full EM spectrum? - ANSWER -Visible Spectrum.
Rutherford - ANSWER --gold foil experiment
-atoms mostly empty space
-small, dense, positively charged nucleus
Gold foil experiment - ANSWER --most particles went straight through
-every once in awhile particles were deflected
-1/8000 particles bounced back
-led to model of atom; small, dense, positively charged nucleus
Atomic Emission Spectrum - ANSWER -Spectrum that emits photons, energy
diagram: electron goes down energy levels.
neutrons - ANSWER --discovered in 1932
-slightly heavier than protons
Atomic Absorption Spectrum - ANSWER -Spectrum that absorbs photons, energy
diagram: electrons goes up in energy levels.
Current model of atom - ANSWER --nucleus contains protons and neutrons
-cloud of electrons
Heisenberg Uncertainty Principle - ANSWER -Principle states that we can't
accurately measure both the position and the energy of a small particle (electron)
Bohr's model did - why its wrong.
, charges of electrons, protons, neutrons - ANSWER --electrons: -1, 1/3000 amu
-protons: +1, 1 amu
-neutrons: 0 charge, 1 amu
Schrodinger's Wave Equation - ANSWER -Treated electron as waves derived by
mathematical descriptions of energies.
Psi = wave function of an electron
Psi^2 = probability of finding an electron.
force (types) - ANSWER -gravitational, electromagnetic, strong, weak
Atomic Orbitals - ANSWER -Regions of space where electrons with a particular
quantized energy have a high probability of being found, described by quantum
numbers.
gravitational force - ANSWER -attraction between objects that have mass.
requires 2+ objects
Fg=Gm1m2/r^2
What are the quantum numbers? - ANSWER -n, l, ml, and ms.
electromagnetic force - ANSWER -attraction/repulsion between objects with
electrical charge
Fe=Q1Q2/r^2
What does quantum number "n" mean? - ANSWER -Determines the energy of the
electron and identifies its shell.
change in matter is accompanied by a change in_______ - ANSWER -energy
What does quantum number "l" mean? - ANSWER -Identifies the type of orbital
(s,p,d) and subshell
= 0 - n-1.
ANSWERS VERIFIED 100% CORRECT
Dalton's atomic theory (1800s) - ANSWER --elements composed of small,
indivisible, indestructible, particles (atoms)
-all atoms of each element are identical (mass/properties)
-no subatomic particles
-compounds are formed by combos of atoms from 2+ elements
-chemical reactions occur from rearrangement of atoms
What increases the number of electrons to be emitted by the photoelectric effect? -
ANSWER -Intensity.
JJ Thomson - ANSWER --first person to provide evidence of electron
-cathode ray tube
-plum pudding model
-particles carried electric charge
A particle that transfers light energy with a definable energy, emits one electron
energy of = h (6.626 x 10^-34 J) - ANSWER -Photon.
cathode ray tube - ANSWER --JJ Thomson
-electron particles were emitted from cathodes
-particles carried electric charge
-ray was independent of the element it came from
-particles identical regardless of cathode
-proved all atoms contained electrons
Energy of light equation? - ANSWER -E = hV.
plum pudding model - ANSWER --atoms contained electrons embedded in the
middle
-JJ Thomson
,h - ANSWER -Planck's constant, the energy of a photon.
alpha particle - ANSWER -2 neutrons, 2 protons
What happens to the energy when there is a short wavelength? - ANSWER -High
energy.
Light from the sun (white light) can be separated by a prism to create this, only a
small part of the full EM spectrum? - ANSWER -Visible Spectrum.
Rutherford - ANSWER --gold foil experiment
-atoms mostly empty space
-small, dense, positively charged nucleus
Gold foil experiment - ANSWER --most particles went straight through
-every once in awhile particles were deflected
-1/8000 particles bounced back
-led to model of atom; small, dense, positively charged nucleus
Atomic Emission Spectrum - ANSWER -Spectrum that emits photons, energy
diagram: electron goes down energy levels.
neutrons - ANSWER --discovered in 1932
-slightly heavier than protons
Atomic Absorption Spectrum - ANSWER -Spectrum that absorbs photons, energy
diagram: electrons goes up in energy levels.
Current model of atom - ANSWER --nucleus contains protons and neutrons
-cloud of electrons
Heisenberg Uncertainty Principle - ANSWER -Principle states that we can't
accurately measure both the position and the energy of a small particle (electron)
Bohr's model did - why its wrong.
, charges of electrons, protons, neutrons - ANSWER --electrons: -1, 1/3000 amu
-protons: +1, 1 amu
-neutrons: 0 charge, 1 amu
Schrodinger's Wave Equation - ANSWER -Treated electron as waves derived by
mathematical descriptions of energies.
Psi = wave function of an electron
Psi^2 = probability of finding an electron.
force (types) - ANSWER -gravitational, electromagnetic, strong, weak
Atomic Orbitals - ANSWER -Regions of space where electrons with a particular
quantized energy have a high probability of being found, described by quantum
numbers.
gravitational force - ANSWER -attraction between objects that have mass.
requires 2+ objects
Fg=Gm1m2/r^2
What are the quantum numbers? - ANSWER -n, l, ml, and ms.
electromagnetic force - ANSWER -attraction/repulsion between objects with
electrical charge
Fe=Q1Q2/r^2
What does quantum number "n" mean? - ANSWER -Determines the energy of the
electron and identifies its shell.
change in matter is accompanied by a change in_______ - ANSWER -energy
What does quantum number "l" mean? - ANSWER -Identifies the type of orbital
(s,p,d) and subshell
= 0 - n-1.
