Test 10/8/14 Flashcards
What did Planck do?
Quantization, “this not that”
What did Einstein do?
Photoelectric effect
What did Balmer do?
He created a wavelength equation but, couldn’t explain it.
What did Bohr do?
Energy levels in hydrogen
What did Heisenberg do?
Uncertainty principle
What did Schrodinger do?
Quantum mechanics
What did Pauli do?
Exclusive principle
Which among the following are not quantized: a) shoelaces b) cars passing through a toll plaza every day c) birds in an aviary d) flow of a river in ml/hr e) percentage of salt in a solution
D
Which of the following are quantized: a) canned soup from a grocery store b) weight of jelly beans c) elevation of a person on a ramp
A
In the Bohr model of the hydrogen atom, the electron occupies distinct energy states. In one transition between energy states, an electron moves from n= 1 to n= 2. Is energy absorbed or emitted in the process? Does the electron move closer to or further from the nucleus?
Absorbed, further
What must be done to an atom, or what must happen to an atom, before it can emit light?
It must get excited.
What experimental evidence leads us to believe that electron energy levels are quantized?
Because atoms emit certain colors.
Which atom is more apt to emit light, one in the ground state or one in the excited state? Why?
Excited because it means the atom can fall.
According to Bohr, what happened when an electron absorbs a photon?
It would get excited.
What does E= hf stand for?
E= energy (J) h= Planck’s constant, (6.63 x 10^-34) (J) f= frequency (Hz)
What does c= (lambda)f stand for?
c= speed of light (3 x 10^8) (m/s) lambda= wavelength (m or nm) f= frequency (Hz)
How many eV’s in one Joule?
1.6 x 10^-19
1s has __ e-? 3p? 5d? 7f?
2, 6, 10, 14
When you do a question that asks for a transition between energy levels use which equation?
1/ lambda = 1.097 x 10^7 ( 1/hf^2 - 1/hi^2)
A visible wavelength is between ____ and ____?
400 and 700
A UV wavelength is shorter than ____?
400
An infrared (IR) is bigger than ____?
700
Ei = hf + Ef, what are the 4 steps? (10 Point Bonus on Test)
(1) hf = Ei - Ef (2) hc/lambda = -Rh/ni^2 - -Rh/nf^2 (3) hc/lambda = Rh ( 1/nf^2 - 1/ ni^2) (4) 1/lambda = Rh/hc (1/nf^2 - 1/ni^2)
What does E = -Rh/n^2 stand for?
E= energy (J) -Rh = -13.6 (eV) n= energy level (1, 2, 3, 4, etc)
