fill in the blanks -13
The emission spectrum of ….. is one of the most thoroughly
studied spectra.
hydrongen
Light is quantized and its quanta are called ….
photons
On the atomic scale, many physical variables are “ ….. “ which means that they can take only
certain discrete values, and all other values are forbidden
quantized
Electromagnetic waves propagate freely through ….
empty space
Electromagnetic waves are … waves.
trasverse
The fact that light can be …. is the evidence of its wave nature.
polarized
Polaroid materials transmit only light with electric field vectors …. to their „pass“ direction.
Parallel
The wave nature of light is demonstrated by the separation of white light into separate
frequency bands in a ….
prism
The energy of a photon obeys the relations … , where …… .
e= hf, h=plank constant, f=frequency
It is experimentally observed that changing the color of the light toward the blue end of the
visible spectrum increases the …. of the ejected electrons.
maximum speed
the maximum kinetic energy of the ejected electrons can be calculated using the relationship....., where W represent the ...... required to remove an electron from the metal surface
emax= hf - w, work
A photon can be visualized as a …. which possesses some wave characteristics but is
localized in space to the extent to demonstrate particle-like properties under appropriate
conditions.
packet of eneergy
It was predicted by … that a particle of mass m moving with
a velocity v would demonstrate a wavelength lambda according to the
equation … where h is Planck ́s constant.
the Broglie , λ =h \ mv
An electron microscope is a device that uses … instead of light for the imaging of objects.
electrons
The study of the electrons and the outer structure of the atom is termed „ …. “ to distinguish it
from „ …. physics,“ the study of the nucleus itself.
quantum , nucleus
The electrons can occupy only certain preferred … levels and they are not observed at other
levels which are said to be „ … “.
energy , forbidden
Another way to express the limitation of the electron energies to specific, discrete values is to
say that the energy is „ … “.
quantized
In the hydrogen atom the electron will normally be found in the n=1 state, which is referred to
as … state.
ground
The … is the energy which an electron would attain by beeing accelerated by … V of electric
potential difference.
electron volt, 1
The … quantum number … specifies the orientation of the orbit.
magnetic, m
… principle states that no two electrons in an atom can exist with the same set of quantum numbers n,l,m and s
paulin esclusion
The study of the selective absorption or emission of electromagnetic waves is known as ….
spectroscopy
The … of solid objects are often the result of selective … .For example, a green object absorbs
the whole visible spectrum except green, which is reflected to provide the perceived color.
colors, absoption
Electromagnetic waves are classified according to their frequency as
radio waves, microwaves; infrared, visible light, ultraviolet, … and
… rays.
X, γ(gamma)
If during the light propagation, the light vector always lies in a plane defined by the direction of
the propagation and the direction of the electric field vector, then the light is said to be …
plane polarized
The smallest resolvable object is comparable in size to the … of the radiation used to view it.
wavelenght
When sunlight is reflected from a flat surface, it is partially polarized in the plane … to that
surface.
Parallel
When no light is seen to emerge from the analyzer, then the polarizer and analyzer are said to
be …
crossed
The … nature of the electron implies that a beam of electrons can be refracted, reflected and
focused to form an image.
wave
.In an electron microscope, … are used to focus the electron
magnetic field