One isotope differs from another in the number of neutrons they have.
The answer is D I hope this helps you !
In an exothermic reaction, heat is produced along with products. But in endothermic reaction, heat is absorbed. If the number of products is less than the sum of the enthalpies of the reactants, the reaction will be exothermic. If the number of products is more than the sum of the enthalpies of the reactants, the reaction is endothermic.
Theoretical yield of Al₂O₃: 1.50 mol.
<h3>Explanation</h3>
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How many moles of aluminum oxide formula units will be produced <em>if</em> aluminum is the limiting reactant?
Aluminum reacts to aluminum oxide at a two-to-one ratio.
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As a result, 3.00 moles of aluminum will give rise to 1.50 moles of aluminum oxide.
How many moles of aluminum oxide formula units will be produced <em>if</em> oxygen is the limiting reactant?
Oxygen reacts to produce aluminum oxide at a three-to-two ratio.

As a result, 2.55 moles of oxygen will give rise to 1.70 moles of aluminum oxide.
How many moles of aluminum oxide formula units will be produced?
Aluminum is the limiting reactant. Only 1.50 moles of aluminum oxide formula units will be produced. 1.70 moles isn't feasible since aluminum would run out by the time 1.50 moles was produced.