<span>The rare earth elements include the lanthanide series, scandium and yttrium. They are a set of seventeen chemical elements in the periodic table. They really are not that rare but they occur together in nature and are hard to separate from one another.</span>
Delta enthalpy = 2x386-3x1x432-3x942=-3350kJ/mol
Answer:
They are:
H2, N2, O2, F2, Cl2, Br2, and I2.
Note: whether the element At molecule is monoatomic or diatomic is incredibly arguable. While some say it exists as diatomic because it is a halogen like bromine, iodine etc, At is in fact extremely unstable and no one has ever really studied the molecules on it, so, when others say it is monoatomic, this is also based on calculations. But the other 7 elements listen above is for sure diatomic.
Answer:
2 NO (g) → N2 (g) + O2 (g)
2 NOCl (g) → 2 NO (g) + Cl2 (g)
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2NOCl (g) ⟶ N2 (g) + O2 (g) + Cl2 (g)
ΔH = [90.3 kJ x 2 x -1] + [-38.6 kJ x -1 x 2] = -103.4 kJ
The ΔH for the reaction is -103.4 kJ
Answer:
Weather can have many classification, how hot how windy how cold how humid. There are however different classifications for different types of weather. Hope this helps :)
