What key event took place during the atomic epoch?
A) The universe expanded and cooled enough to allow the first particles to appear.
B) The universe expanded and cooled enough for electrons to orbit protons.
C) The neutrinos were created.
D) Atoms in the universe collected to form stars and galaxies.
E) The universe underwent a brief period of rapid expansion.
B
You might also like to view...
Exhibit 13-1
Two blocks of masses m1 and m2 are connected by a light cord that passes over a pulley of mass M, as shown. Block m2 slides on a frictionless horizontal surface. The blocks and pulley are initially at rest. When m1 is released, the blocks accelerate and the pulley rotates.
?
?
Use this exhibit to answer the following question(s).
Refer to Exhibit 13-1. The total angular momentum of the system of the two blocks and the pulley relative to the axis of rotation of the pulley is
A. the same at all times. B. proportional to l1, the length of string from the pulley to m1. C. proportional to l2, the length of string from the pulley to m2. D. conserved because the Earth doesn't move. E. proportional to the speed of the blocks.
What reaction would be taking place if you were charging the battery?
In a battery, if the following oxidation-reduction reactions takes place normally: Mn2O3 + ZnO ? 2 MnO2 + Zn A) 2 MnO2 + Zn ? Mn2O3 + ZnO B) ZnO ? Zn C) Mn2O3 ? MnO2 D) all of the above E) none of the above
If the relative mass of a pingpong ball is 1/20 that of a golf ball, how many pingpong balls would you need to equal the mass of two golf balls?
A) 40 B) 20 C) 24 D) 100 E) 6.022 × 1023
____________________ formed as Mercury cooled and shrank
Fill in the blank(s) with correct word