What is the period of an objects motion?

The star betelgeuse is about 600 light-years away. if it explodes tonight, a. we'll know because debris from the explosion will rain down on us from space. b. we'll know it immediately because it will be brighter than the full moon in the sky. c. we won't know about it until 600 years from now. d. none of the above.

Which compound is held together by the electrostatic force between two ions? a. co2 b. cci4 c. h2s d. mgf2

The total amount of energy contained in an object