3 Cu + 8HNO3 --> 3 Cu(NO3)2 + 2 NO + 4 H2O In the above equation how many moles of water can be made when 109.9 grams of HNO3 are consumed?

If e is the symbol for an element, which two of the following symbols represent isotopes of the same element? 1. e2. e3. ea.1 and 2c.1 and 4b.3 and 4d.2 and 3