6.52 × 10⁴ L. (3 sig. fig.)
<h3>Explanation</h3>
Helium is a noble gas. The interaction between two helium molecules is rather weak, which makes the gas rather "ideal."
Consider the ideal gas law:
,
where
is the pressure of the gas,
is the volume of the gas, 
is the number of gas particles in the gas, 
is the ideal gas constant, and
is the absolute temperature of the gas in degrees Kelvins.
The question is asking for the final volume of the gas. Rearrange the ideal gas equation for volume:
.
Both the temperature of the gas, , and the pressure on the gas changed in this process. To find the new volume of the gas, change one variable at a time.
Start with the absolute temperature of the gas:
,
.
The volume of the gas is proportional to its temperature if both and stay constant.
- won't change unless the balloon leaks, and
- consider to be constant, for calculations that include .
.
Now, keep the temperature at 
and change the pressure on the gas:
,
.
The volume of the gas is proportional to the reciprocal of its absolute temperature 
if both and stays constant. In other words,
(3 sig. fig. as in the question.).
See if you get the same result if you hold constant, change , and then move on to change .
Answer:
B.) trigonal bipyramidal
Explanation:
A.) is incorrect. In octahedral molecules, the central atom is bonded to six other atoms.
B.) is correct. In trigonal bipyramidal structures, the central atom is bonded to five other atoms.
C.) is incorrect. In tetrahedral molecules, the central atom is bonded to four other atoms.
D.) is incorrect. There is not such thing as a pyramidal molecular shape. This term is most likely referring to the shape, trigonal pyramidal. However, this is still incorrect. In trigonal pyramidal molecules, the central atom is bonded to three other atoms and a lone pair of electrons.
