Why does a solid change to liquid when heat is added?

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 the constituent metals of stainless steel?

In an exothermic reaction, energy may be released to the surroundings in the form of question 4 options: heat light thermal all of the above