Author Question: Planetary orbits are a. parabolas c. circles b. ellipses d. none of the ... (Read 113 times)

809779 · **on:** Jul 28, 2018

Planetary orbits are
a. parabolas c. circles
b. ellipses d. none of the above.

Question 2

What is a curie?
a. The unit of speed of radioactive decay.
b. The same unit as an alpha particle or a helium nucleus.
c. The half-life of an isotope expressed as a rate instead of a time (i.e., per second instead of seconds).
d. The unit that measures the number of decays in each unit of time that are occurring in a sample.
e. The unit of momentum of a radioactive particle.