The second most abundant element in the solar system is
A) silicon. B) helium. C) oxygen. D) hydrogen. E) carbon.
Question 2
How do we know the expansion of the universe is accelerating?
A) We're really not that sure the expansion is accelerating; it's all just a theory.
B) The rotation curves of galaxies indicate the universe is speeding up.
C) White dwarf supernova in distant galaxies are fainter than they would be if the expansion were not accelerating.
D) Redshifts of distant galaxies are increasing with time, so when we repeat the measurements, the redshifts are larger.
E) We see more of the universe every night, as the observable universe grows in size.
Polaris system
Taken by Hinode's Solar Optical Telescope on January 12, 2007, this image of the Sun reveals th
The autonomic nervous system with its sympathetic and parasympathetic divisions
Pathways of the Auditory System
How Orbital Eccentricity Changes the Amount of Solar Radiation Earth Receives
The two skills of the element Selection of Alternatives