Student B because it requires a hypothesis
Answer:
From Earth, the Sun looks like it moves across the sky in the daytime and appears to disappear at night. This is because the Earth is spinning towards the east. The Earth spins about its axis, an imaginary line that runs through the middle of the Earth between the North and South poles.
Explanation:
Answer : The molecular weight of a substance is 157.3 g/mol
Explanation :
As we are given that 7 % by weight that means 7 grams of solute present in 100 grams of solution.
Mass of solute = 7 g
Mass of solution = 100 g
Mass of solvent = 100 - 7 = 93 g
Formula used :

where,
= change in freezing point
= temperature of pure water = 
= temperature of solution = 
= freezing point constant of water = 
m = molality
Now put all the given values in this formula, we get


Therefore, the molecular weight of a substance is 157.3 g/mol
Explanation:
there is 2 nitrogen but if you mean nitrate is 6
Answer:
Nitrogen, 
Explanation:
Hello,
This is a clear example of what the ideal gas equation is used for, thus, from its mathematical definition:

One can spell it out in terms of mass and molar mass:

Now, solving for the molecular mass,
:

Now, by taking into account that the gas is diatomic, the matching gas turns out to be nitrogen.
Best regards.