Why are ionic compounds not considered mixtures based on their atomic structure? List 2 ways that a formula unit is different from a molecule?

Does anyone know a lot about how to: - calculate mass of magnesium metal - calculate the actual yield of magnesium oxide - calculate the theoretical yield of mgo - calculate the percent yield of mgo - determine the percent yield of mgo - determine the average percent yield of mgo i had to do an online lab and its asking these questions but i have no idea where to start or how to be able to find these things. i can post the chart of the data from the lab or if you can tell me exactly how i can find each.

What are transitions between a liquid and a solid called? identify which way they are transitioning

George is a dalmatian puppy. describe what happens to light that allows you to see george’s black and white coat.