Answer:
the second one seems right :)
Explanation:
Independent variable: the student chooses to miss class.
dependent variable: in result of the student missing class his grade goes down.
hyposthesis: if the student misses class multiple times, then his grades will go down.
The number of moles of NH3 that could be made would be 0.5 moles
<h3>Stoichiometric reactions</h3>
From the balanced equation of the reaction:
N2 (g) + 3 H2(g) ----> 2NH3 (g)
The mole ratio of N2 to H2 is 1:3
Thus, for 0.50 moles of N2, 1.5 moles of H2 should be present. But 0.75 moles of H2 was allowed to react. Meaning that H2 is limiting in this case.
Mole ratio of H2 and NH3 = 3:2
Thus for 0.75 moles H2, the mole of NH3 that would be produced will be:
2 x 0.75/3 = 0.5 moles
More on stoichiometric calculations can be found here: brainly.com/question/8062886
The two main types of chemical bonds are ionic and covalent bonds. An ionic bond essentially donates an electron to the other atom participating in the bond, while electrons in a covalent bond are shared equally between the atoms. The only pure covalent bonds occur between identical atoms.
I think the correct answer from the choices listed above is option A. The three components of air are all <span>classified as pure substances since they are not chemically bonded so they can be separated by certain processes and be present as a pure substance. Hope this answers the question.</span>