For this question, lets apply Avagadro's law
when Pressure and temperature are constant, the volume occupied is directly proportional to the number of moles of gases.

where V-volume, n-number of moles and k - constant
Therefore at 2 instances

where V1 and n1 are for 1st instance
and V2 and n2 are for 2nd instance
therefore

V1 = 2.4 L
n1 = 3.7 mol
n2 = 3.7 + 1.6 = 5.3 mol
since more He moles are added at the 2nd instance its the sum of the moles.
V2 needs to be calculated

V2 = 2.4 x 5.3 / 3.7
= 3.4 L
Answer is 1st option 3.4 L
Liquid - rain
Solid - snow
Gas - water vapour (when it evapourates from the lithosphere)
I think the correct answer from the choices listed above is the first option. The element that has the highest standard reduction potential would be fluorine. Hope this answers the question. Have a nice day. Feel free to ask more questions.
Answer:

Explanation:
Hello,
In this case, for such formation of sulfur hexafluoride, the standard enthalpy of formation is -1220.47 kJ/mol (data extracted from NIST database). Next, we compute the moles in 10.0 grams of sulfur hexafluoride as shown below:

Next, for the given energy, we compute the total heat that is liberated:

Finally, we conclude such symbol has sense since negative heat is related with liberated heat.
Best regards.
Answer:
C
Explanation:
1. The molecule has to have a ratio of 1 hydrogen to 1 oxygen.
2. Hydrogen = 1amu, Oxygen = 16amu. (2*2)+(16*2) = 34amu