Answer:
74.344 kJ.
Explanation:
Below is an attachment containing the solution.
Fluorine (F) will have properties similar to Bromine (Br) because it belongs to the same group as Bromine.
The answer is B...
because any of the others could have an opinion based answer but B will always be the same its a fact not opinion.
D Microscopes
because they use them for DNA
a,b,and c, all you an item that can be used and not tested with.
Let us suppose that we have 1 mol of FeCr2O4. I'm going to use approximate masses because I have no idea what your periodic table will say. Just put in the exact masses from your periodic table.
Fe = 56
Cr*2 = 2*52 = 104
O4 = 4*16 = 64
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Total = 56 + 104 + 64 = 224
The % oxygen = (64 / 224) * 100 = 28.5 % but none of your answers match this. Perhaps you are talking about Fe2(Cr2O4)3 The brackets make all the difference in the world.
Without going through all the detail I did before, The molecular mass is
Fe * 2 = 112
Cr * 6 = 312
O * 12 = 192
The total molecular mass = 616
The % Oxygen = (192 / 616) * 100 = 31% roughly. That answer isn't there either.
Let's wait and see who else answers.
