Which of the following statements is true about the very early universe (within the first three minutes)?

a. The electroweak force was the force believed to have first separated from the others.
b. The entire first three minutes can be explained by applying a grand unified theory.
c. Electrons only formed after the protons and neutrons.
d. The end of the first three minutes signaled the first probable nucleosynthesis.
e. By about 1 second, the universe was about half the present size.

d.
By the end of the first three minutes, the universe had cooled enough for the nuclear strong force to take effect and nucleons bound together to form deuterons.

Physics & Space Science

You might also like to view...

A piece of wood is floating in a bathtub. A second piece of wood sits on top of the first piece, and does not touch the water. If the top piece is taken off and placed in the water, what happens to the water level in the tub?

A) It goes up. B) It goes down. C) It does not change. D) It cannot be determined without knowing the volumes of the two pieces of wood.

View
Physics & Space Science

Going from oldest to youngest, the three periods of the Mesozoic are

A) Triassic, Jurassic, and Permian. B) Jurassic, Triassic, and Cretaceous. C) Triassic, Jurassic, and Cretaceous. D) Cretaceous, Permian, and Jurassic.

View
Physics & Space Science

"MeV/c2" is a unit for:

a. energy. c. mass. b. nuclear force. d. momentum.

View
Physics & Space Science

Say that our Moon was Full on May 1, 2007. When was the next First Quarter phaseafter that Full Moon?

a) May 15 b) June 1 c) May 22 d) May 8 e) May 4

View
Physics & Space Science