I would say it is a chemical change because after a while, the nails start to rust. Now they only rust after about a week though. But rust is a chemical change.
Answer: The correct option is B. A farmer with a field of solar panels
Explanation: Since the question says that the students are related to environmental group so they must run a campaign for the renewable energy resources and avoid the use of natural non renewable resources. coal, gas and many others like these are non renewable sources of energy. A farmer using solar panels in his field must be appreciated because he is using an environment friendly source of energy.
........................................................................
Liquidity metric is the other name
We will assume helium to behave as an ideal gas and apply the ideal gas law:
PV = nRT
For pressure measured in atmospheres and volume measured in liters, the value of the molar gas constant is 0.082. Therefore:
T = PV / nR
T = (2.57 x 15.5) / (1.2 x 0.082)
T = 404.8 Kelvin