Hi there!
Deep sea divers CANNOT use pure oxygen in their tanks. Pure oxygen is deadly, and can kill them. This would be called Oxygen toxicity
Hope this helps you!
~DL ☆☆☆
Answer:
I'm not a genius but it's an invisible force that pulld object towards eachother, Earth's gravity is what keeps you on the ground and what makes things fall, Anything with mass also has gravity, objects with more mass means they have more gravity
Answer:
It's determined by the ability of one mineral to scratch another mineral.