After nuclear reactions in the big bang had ended, about 25% of the mass of the Universe was in the form of helium nuclei
a. True
b. False
Indicate whether the statement is true or false
True
You might also like to view...
Describe the measurements needed to determine the orbit of a visual binary star
What will be an ideal response?
What happens when a particle of matter and its corresponding particle of antimatter meet?
A) No one knows, since antimatter is only theoretical and not known to really exist. B) The particles join together to make an antimatter atom. C) The particles collide and then bounce back apart. D) The particle and the antiparticle are annihilated, turning all their mass into energy. E) They live happily ever after.
That brighter Sirius A weighs 3 solar masses, but the white dwarf Sirius B is only about one solar mass implies:
A) that white dwarfs evolve slower than main sequence stars. B) that the collapsed companion transferred mass to Sirius A. C) that there should be a planetary nebula around the Sirius system. D) that Sirius A will be stable three times longer than Sirius B. E) the Sirius A will end up as a black hole, not a white dwarf like its companion.
The acceleration of a ball as it rolls down a ramp is 4 m/s2 . The ball is referred to 2 s after it starts to roll. The velocity acquired after starting from rest in m/s is
a. 0. b. 2. c. 4. d. 8. e. 16.