Given: CNO2 a) Draw the Lewis structures (Do not forget to show the calculation of the number of available valance electrons)

b) Name the geometry shape

c) Indicate the polarity (polar or non-polar)

since there are no lone pairs on the central atom, this would be a trigonal planar molecule. It's polar because the shape of it does not cancel its polarity (you can think of it as not having a balanced electronegativity pull, since the nitrogen is pulling on one side, and the oxygens are pulling on the other. It would be nonpolar if the there were 3 Oxygens).

Sorry this take a little bit long. I was a little confused by the odd valence number

c. heat could easily travel through the molecules in the air and escape/enter the flask. removing the air slows down the heat transfer.  

nacl or sodium chloride is an ionic compound. this is because an ionic compound pertains to a compound that consists of positively and negatively charged ions. in this case, na (sodium) has a tendency to lose one electron when it reacts with with other atoms, so the resulting sodium ion contains 11 protons and 10 electrons, thus making it positively charged (na+), when chlorine reacts, it usually gains one electron to form an ion called chloride, thus making it negatively charged ( since the ions are oppositely charged, they attract.