Answer:
Calcium would displace barium.
Explanation:
Ba(NO₃)₂ + Ca --> Ca(NO₃)₂ + Ba
There are two types of compounds: molecular/covalent and ionic.
Molecular/covalent compounds are non-metal + non-metal.
Ionic compounds are metal + non-metal.
Looking at the periodic table, barium is a metal. Calcium is also a metal.
Checking a polyatomic ions chart would tell you NO₃⁻ is a non-metal because it has a negative charge.
Since there is no metal + metal compound, the calcium metal would displace barium. The compound remains ionic.
Answer:
C. Solids made of molecules
Argon is a suitable choice for light bulbs because it's inert. Compared to a reactive gas like oxygen, the metal filimant would burn up in a reactive enviroment, which is why a noble gas is used.
I think it is D I'm not positive
