Atomic and Nuclear Physics Answers

Explain that what peaks in binding energy curve shows in details?

A water drop of radius 10^-5cm is given a charge 1.6× 10^-19c.If it floats in a electric field,what is the intensity of the electric field?

Quantum mechanics says that, given a situation, the most we can know about an electron's position in an atom is before doing an experiment is
A. where it can be and where it can't be
B. the probability of where to find it
C. the energy level it is in
D. its distance from the nucleus (the radius of its circular path)

probability?

verify my answer please
1. A solar cell, which makes up solar panels, creates electricity by means of the photoelectric effect. If a solar cell only produces a current when one of these colors of light is used then the color that works is
A. green
B. orange
C. red
D. blue
E. yellow
=> D?
2. What causes the dark lines in the absorption spectrum of an element to occur ?
A. Photons are absorbed when electrons jump from a higher-energy to a lower-energy state.
B. Photons are emitted when electrons jump from a higher-energy to a lower-energy state.
C. Photons are absorbed when electrons jump from a lower-energy to a higher-energy state.
D. Photons are emitted when electrons jump from a lower-energy to a higher-energy state.
=>C?
3. The atomic model Bohr developed was revolutionary in that
A. the electrons traveled around the nucleus in circles
B. the was a nucleus with electrons outside the nucleus
C. the electrons had a wavelength
D. the electrons had only certain allowed energies
=>A?

Can you help me verify these answers?
1. An X-ray photon collides with a stationary electron. How does the frequency of the scattered photon compare to the frequency of the photon before being scattered?
A. The new frequency is higher.
B. The new frequency is lower
C. The frequency stays the same.
D. The scattered photon has no frequency, as it acts like a particle
==> A?
2. When light shines on a metal cathode in a vacuum tube
A. electrons may be ejected
B. electrons are always ejected
C. protons may be ejected
D. protons are always ejected
==> B?
3.Einstein’s theory of photons explained the experimental results of the photoelectric effect by saying
A. the electrons had quantized energy levels
B. the light’s frequency determines the photon’s energy, and the energy must be more than the work function
C. the electron’s position is not known, only the probability of where to find it
D. the frequency of the light has to be more than a certain, threshold frequency
==> B?

Can you verify my answer?
1. Scientists were originally confused by the photoelectric effect because they expected the ejection of electrons to be most greatly affected by the light’s
A. wavelength
B. speed
C. intensity
D. frequency
==> C?

2. The energy of a photon is directly proportional to its _____
==> frequency?

3. Max Plank developed a mathematical equation that described the intensity of the light spectrum produced by blackbody radiation. He did so by assuming that
A. the light emitted created an emission spectrum
B. classical physics was wrong
C. the energy of the “resonators” was quantized
D. the number of electrons was quantized
==> C?

A radioactive tracer used in a medical test has a half-life of 2.6 h. What proportion of this tracer
will remain after 24 h?

1. During the deep X-ray therapy high energy X-rays are used. They are filtered by passing them through copper
and aluminium plates. If the copper plate has thickness

2. A vial contains 1900 MBq of Technetium-99m on the 18th June 2014 at 06:00. How much will it contain at 07:00 on the 19th June 2014? Please input your answer in Bq and Ci.

E. The radioactive nuclide Plutonium-199 has a half-life of 43.0 min. A sample is
prepared that has an initial activity of 7.56 ×1011 Bq.
i. How many Plutonium-199 nuclei are initially present in the sample?
ii. How many are present after 30.8 min?
iii. What is the activity at this time?