It is tempting to think that some materials are always heavier than other materials. For example, someone might say that metal is heavier than air. But it depends on how much of each material there is ...

Copper atoms are larger than aluminum atoms. There are fewer copper atoms than aluminum atoms in the cubes. Copper atoms are much more massive than aluminum atoms. The extra mass makes copper more ...

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Hi, I'm Diana. Great to be here with you today. I was wondering why is it that a golf ball and a ping ...