D. Strands of seaweed. I am not so sure if this is the correct answer but it might.
Answer:

Explanation:
Hello
In this case, given the reaction:

It means that since the coefficients preceding phosphorous and phosphorous trifluoride are 1 and 4, the correct mole ratio should be:

Because given the mass of phosphorous it is convenient to convert it to moles and then cancel it out with the moles on bottom of the mole ratio.
Bes regards!
B is correct because it doesn't depend on the movement just how the partials move at boiling point, ie it will expand but not gain motion
Answer:
121.63 g/mol
Explanation:
Sr(OH) 2 = Strontium Hydroxide