Ca3(PO4)2 is the correct formula.
Answer: Option (a) is the correct answer.
Explanation:
Under conditions of low pressure and high temperature, gas molecules exhibit negligible attractions or repulsions among themselves. Hence, gases behave ideally in these scenarios.
Conversely, at low temperatures, there is a reduction in the kinetic energy of gas molecules, while high pressure compels the molecules to be closer together.
Thus, attractive forces emerge between molecules in conditions of low temperature and high pressure, causing gases to be termed real gases.
Therefore, we conclude that the ideal gas law becomes less accurate when pressure increases and temperature decreases.
The change in temperature can be expressed as:

By substituting in the known values, we arrive at:

Thus, we obtain the required answer.
To determine the answer, you need to understand the formula for converting grams to moles, which will then lead you to the number of molecules.
The result is 2 moles of N2O5. The process is as follows:
(0.25 g N2O5) (1 mol/ 108 g)=2.31 molecules
Thus, the final answer is 2 molecules.
Yasir wished to explore how sleep relates to room color. He conducted necessary preliminary research and formed a hypothesis suggesting individuals doze off faster in blue-painted rooms compared to those painted in yellow. Yasir surveyed several individuals about their color preference—yellow or blue—and utilized their feedback to assess the validity of his hypothesis. However, he did not conduct an actual experiment to examine the impact of room color on sleep, and he failed to clearly define the variables that should have been part of his experiment.
Hence, the correct answer would be,
An experiment that directly tests the hypothesis
Variables to be tested by an experiment