From my high school chemistry class almost 60 years ago --
Use a magnet to pull out the iron filings. Water will dissolve the salt. The sawdust will remain.
1.How would you separate a mixture of salt, sawdust, and iron filings?
2. The Mg^2+ and Na^+ ions have ten electrons. Which has the smaller radius? Explain.
2 answers
Ms. Sue remembers her chemistry from 60 years ago. Yea!
For #2,consider the charge on the Na nucleus versus the charge on the Mg nucleus.
For #2,consider the charge on the Na nucleus versus the charge on the Mg nucleus.