Answer: It is true that Your friend should release the 
first.
Explanation:
The velocity of particles of a gas is inversely proportional to the mass of gas. This means that more is the mass of gas less will be its velocity.
Or, more will be the mass of gas more slowly it will move from one place to another.
The molar mass of chlorine gas is more than the molar mass of hydrogen gas. Therefore, chlorine gas will move slowly.
So, your friend should release the gas first and then according to the length of room you should release the 
gas.
Thus, we can conclude that it is true that Your friend should release the first.
The correct answer is Be+
That is because it lost a single electron but still has the same number of protons, and thus the effective charge attracting each electron is greater, which in turn makes the radius even smaller
Explanation:
IM PRETTY SURE IT IS D !! IF ITS WRONG IM SORRY THAT WHAT
I GOT
Excuse me not giving an explanation; I haven't even learned chemistry before. I usually give explanations for math/english.
I think it would be for flourine: 7
aluminum: 8
can't help with the rest...
sorry!
<span>A. Mechanic agitations</span>
