true and false 13
According to the classical concepts, mass, velocity, acceleration, and other quantities have a
continuous range of values.
T
Unlike sound or water waves, electromagnetic waves require a material medium through which
to travel.
F
When electromagnetic waves propagate through a material medium, their effective speed is
higher than the free-space speed
F
Light from the sun contains waves with electric field vector oscillating in all possible directions
perpendicular to its propagation direction.
T
When light of high enough frequency falls on the surface of a metal such as sodium, electrons
are emitted from the surface by photon-electron interactions within the metal.
F
Experimentally, increase in light intensity increases the number of the electrons ejected and their
maximum velocity.
F
Light has no rest mass and cannot be stopped and localized at a particular point. ( )
T
The dependence of light intensity upon the frequency is a crucially important concept in modern
physics.
T
A photon of blue light has less energy than a photon of red light.
F
Light photons are more energetic than microwave photons and x-ray photons are most
energetic than visible light photons
T
Light exhibits dual nature, i.e. both wave-like and particle-like properties.
V
The wave properties of larger objects are not observable because the wavelengths associated
with them are much greater as compared to their sizes.
F
An electron microscope is used for the observation of small organisms such as viruses and
structural details of cells.
T
Electrons are arranged in energy levels that are labeled by a quantum number m.
F
The quantum number L is called orbital quantum number and specifies the angular
momentum of the electron.
T
The shell configuration is closely related to the chemical behavior of the elements. All
elements have a tendency to either add electrons to fill the outermost shell or to get rid of
electrons to drop back to the next closed shell configuration.
T
The chemical behavior of an element is mainly determined by the innermost electron shell.
F
After excitation, the electron has a strong tendency to jump to one of the lower energy states,
continuing the process until it reaches its ground state.
F
In order to drop to a lower state, an electron must gain energy to be consistent with the
principle of conservation of energy.
F
.The line spectral frequencies for a given element are unique and reproducible
T
Emission spectrum may be used to check for the presence of trace quantities of toxic
elements such as arsenic or lead.
T
Photoelectric effect cannot be explained by the wave theory of light.
T
Photons have energies equal to Planck ́s constant divided by the frequency of the light.
F
Each element has a characteristic set of allowed energy levels for its electrons.
T
In polarimeter, there is no any difference between polarizer and analyzer
F
The actual limit of resolution of electron microscope is about 10um.
F
Each proton possesses one quantum of positive charge.
T
In an electron microscope, the resolution can be enhanced by using lower speed electrons.
F
Only photons with energies equal to the separation between allowed energy states can be
absorbed or emitted.
T
Absorption spectroscopy can be used to identify the chemical elements present in stars.
T