Where are the most massive stars to be found in the

Where are the most massive stars to be found in the main sequence of a
Hertzsprung-Russell diagram?
The Sun's spectral curve peaks in the yellow-green region of the spectrum
(i.e., this region is the most intense part of its spectrum). The spectrum of
Rigel (the star in the knee of Orion) peaks in the short-wavelength end of the
visible spectrum. Compared to the Sun, Rigel is d. hotter and bluer.
The luminosity of a star is a unique measure of it .
Atoms in a thin, hot gas (such as a neon advertising sign), emit light
at specific wavelengths or colors, the pattern depending on the element .
Spectral lines are of particular importance in astronomy because
a. each different element has a characteristic line spectrum.
How much longer can the Sun continue to generate energy by nuclear
reactions in its core? d. About 5 billion years
How do astronomers measure the masses of stars? By observing the
motion of two stars in a binary star system
What is the dominant mechanism by which energy is transported through the
inner regions of the Sun?
b. by photons (radiative transport of energy)
If the surface temperatures of white dwarf stars are up to 4 times that of the
Sun, why then are white dwarfs intrinsically so faint? very small
Compared to a star in the middle of the Hertzsprung-Russell diagram, a star
in the upper right part of the diagram is larger .
The granular appearance of the surface of the Sun is evidence of what
phenomenon occurring in or on the Sun?
Which of the following particles or types of radiation will provide the most
direct information on the energy generation processes that are occurring at
the present time in the solar core? c.
A star in the lower left part of the Hertzsprung-Russell diagram, compared to
a star in the middle of the diagram, is Smaller
Two stars have the same luminosity. One star is spectral class B and the
other is spectral class K. From this information, we know that the K-type
star is larger than the B-type star.
How can we characterize the rotation of the Sun?
Differential rotation, with the equator rotating faster than the poles
Two stars, P and Q, can be seen in the same region of our sky with the same
apparent brightness, but star Q is twice as far away as star P. What is the
ratio of the intrinsic brightnesses (luminosities) of these stars (star P-to-star
Q)? c