6. Use the simulation to determine what the mass number and the atomic mass (amu) is for the isotope Fluorine-19.What is the biggest difference you see between the two numbers? Explain why these are different use the isotopes and mixtures simulation by phet
7. What is the percent compositions for nature's mix of lithium isotopes? What do you notice about the average atomic mass compare to the mass numbers for these same lithium isotopes? How does this relate back to how the average atomic mass is calculated.