How did star formation likely proceed in the protogalactic cloud that formed the Milky Way?
A) The protogalactic cloud gradually formed stars, starting from the center of the galaxy working outwards.
B) The protogalactic cloud gradually formed stars, starting from the outer edges of the spiral arms and working inward.
C) The stars that formed first eventually settled into a galactic disk, circling the center of the galaxy.
D) The stars that formed first could orbit the center of the galaxy in any direction at any inclination.
D
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According to our present theory of solar system formation, why were solid planetesimals able to grow larger in the outer solar system than in the inner solar system?
A) The solid material that accreted in the outer solar system included ices, while the solid material of the inner solar system consisted only less abundant metal and rock. B) There was more time for accretion in the outer solar system before the solar wind cleared the nebula away. C) The gas in the outer solar system contained a larger proportion of rock, metal, and hydrogen compound than the gas in the inner solar system. D) Gravity was stronger in the outer solar system, allowing more solid material to collect.
A + 5.0-?C charge is moved from a negative to a positive plate of a parallel plate capacitor. In moving this charge 0.30 mJ of energy is used. What is the potential difference between the plates of this capacitor?
A) 60 V B) 81 V C) 55 V D) 23 V E) 0 V
A diatomic quantum mechanical vibrator in its ground state has energy E. This same vibrator in its third state has energy
A) E. B) 3E. C) 5E. D) 7E. E) 9E.
What happens in electron capture?
a. The nucleus emits an electron, a neutron becomes a proton, and the atomic number goes up. b. The nucleus absorbs an electron, a proton becomes a neutron, and the atomic number goes down. c. The nucleus emits a positron, a neutron becomes a proton, and the atomic number goes down. d. The nucleus emits an electron, a neutron becomes a proton, and the atomic number goes down. e. The nucleus absorbs an electron, a proton becomes a neutron, and the atomic number goes up.