1) What makes the helium in a balloon different from the gold in a ring? Why does the helium float in the air and in water whereas the gold sinks in air and water? (This is just meant for you share what you think.)

2) (Fill in the blank) A 40 gram block of metal has a density of 4 g/mL. The density of a 4 gram block of the same metal is ______ g/mL.

The metal will sink in the water because it is _______dense than the water.

Another block has a density of 0.9 g/mL. This block will _____ in the water.