It is also important to note that brine is an effective preventative for ice formation, but not deicing.
The better option for deicing is rock salt.
Rock salt is most effective for temperatures above 25 degrees. However, rock salt can still melt ice at temperatures below 0 degrees.
Does your child have a weather question you want to see Jesse answer? Send an email to Jesse.Maag@cmgohio.com and you might see Jesse perform an experiment based on your question!