(b) Explain why copper metal cannot be used to prepare hydrogen gas

The answer is falsegravitational force is independent of medium and depends only on the masses of the two objects and the distance between them.

When china's civil war resumed, the nationalists held an advantage because the nationalist had more soldiers  than the communist.

Ibelieve it's alpha and gamma ray particles.

This is because the total  energy transferred  by the battery must equal the amount of  energy transferred  to the other components in the  circuit. the charge then transfers  energy  to the components (bulbs, resistors, etc). more  energy  is  transferred  by charge flowing through a larger resistance than through a smaller one.hope this and mark as brainliest!