Dr. Kent McCorkle, or "Dr. Kent' to his student, has helped thousands of students be successful in chemistry.

Chemistry Lesson: Average Atomic Mass Calculations

[View the accompanying Atomic Mass Practice Problems Part I┬áhere.] Atomic Mass The atomic mass is an experimental number determined from all of the naturally occuring isotopes of an element. As we saw in our lesson on atomic structure, not all … Read More



Chemistry Lesson: Molar Mass

[View the accompanying Practice Problems on Molar Mass Conversions here.] What is Molar Mass? Molar mass is literally the mass of one mole of a substance. We saw in a previous lesson on atomic mass that the periodic table provides us … Read More



Chemistry Practice Problems: Atomic Mass Calculations I

[Download the accompanying PDF worksheet.] Calculate the Average Atomic Mass Calculate the average atomic mass of an element with two naturally occurring isotopes: 85X (72.15%, 84.9118 amu) and 87X (27.85%, 86.9092 amu).  What is this element? Chromium has the following … Read More