the answer is A......
it is supported by practical evidence and examples. this is the answer because he tried and tested many different ways to see what would happen so he is happy with the conclusion that what he tested is what he gets.
Molecular mass of nitrogen, N2 = 2*14 = 28
molecular mass of hydrogen, H2=2*1 = 2
Molecules of both elements contain 2 atoms, so the ratio of molecules is the same as the ratio of atoms.
From the molecular masses above,
ratio of number of molecules = ratio of molecular masses, therefore
7g N2 : x g H2 = 28:2
cross multiply:
x=7*2/28=0.5 g of Hydrogen has the same number of atoms as 7 g of nitrogen (at room temperatures)
Yeah it uses some valuable scientific vocabulary and background knowledge, I hope this hypothesis will be good enough for your teacher (don't worry it will be)
B.
And maybe put your question in the English/Literature tag next time lol
Answer:
2cm^3
Explanation:
Use the density triangle: D=MxV
Switch for variables, V=M/D
Plug in numbers, 15.8g/7.9g/cm^3=2cm^3