When a star reaches the black hole stage of its life

it is a very old star
it will give off new energy
it will grow in size
it is still a young star

Phase changes are chemical changes. true or false

Which are advantages of renewable resources? check all that apply. renewable energy supplies are completely reliable everywhere. some renewable resources will never be used up. little or no waste is produced by renewable resource plants. electricity can be generated in large quantities. many renewable energy facilities have lower operating costs.

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