QUESTIONS WITH SOLUTIONS GRADED A+
◉ The Hubble constant has units of ____________
Answer: 1/time
◉ The Hubble constant tells us that the universe is ______________.
Answer: 13 billion years old
◉ The Hubble constant also tells us that _____________.
Answer: the universe is expanding uniformly
◉ The main asteroid belt lies between the planets ____________.
Answer: Mars and Jupiter
◉ 204Pb and 206Pb are examples of different _______________ of the
element lead
Answer: isotopes
, ◉ One astronomical unit is defined as ______________.
Answer: one earth-sun distance
◉ Looking down on the Earth from the north pole, the planets of our
solar system generally rotate ____________.
Answer: Counterclockwise
◉ Only ___________ have retrograde rotation
Answer: venus, uranus and pluto
◉ The protoplanetary disk that made the solar system was a disk
because ___________.
Answer: A balance between gravitational force and centripetal force
acting on particles near the growing Sun.
◉ Most of the angular momentum in the solar system is in
_____________.
Answer: the planets
◉ The main source of heat in our protoplanetary disk was __________.
Answer: viscosity of the disk
◉ Most meteorites in our possession today are ___________.