An element with a valence of 8 are most likely noble gases (He, Ne, Ar, etc) which means they're already stable so they dont need to undergo chemical bonds with another atom because they already have a full valence shell.
M=F/A
Which means 30 divided by 5 m/s is 6kg(mass)
Answer: It goes inside filling most of it .
Explanation: This happens because the bottle is empty and the bucket is full of water.