1. when the ball is just starting to fall, it has high potential but low kinetic energy. when it hits the floor, it has high kinetic but low potential energy
2. heat energy
3. reflective-transparent would be best, as they can reflect some light while let other light through, reflective-opaque would be useless in any circumstances because no light at all would be able to get through
Basically since there’s 2 hydrogen’s there will be two H’s on either side of your other element. And Se is in group 6 which means it has 6 valence electrons. When you combine 6 and 2 from the hydrogen you get 8. You then should place 8 dots around Se two on each side.
So something like H Se(with 8 dogs around it) H
