If the sealed glass is permeable to sunlight or to transfer of heat will be an open system, but if the sealed glass is a thermic glass and doesn't allow exchange of heat and exchange of solar energy (for example a mirrored glass that reflect the sunlight) and the terrarium is not exchanging energy with the surroundings will be a closed system. It is a question that doesn't specify too many details about the system in the study. It is hard to give a final answer without making some assumptions.
Pretty sure it’s ,B. Microscope!
Radioactivity another name for radioactive decay. Radioactivity refers to particles emitted from nuclei as a result of nuclear instability.
See if the carbon atoms are SP2 or Sp they the coplanirty is more and if its Sp3 hybridization it cant be in coplanar as Sp3 is having Td shape where as sp2 and sp are not :)
Na is the elemental abbreviation for sodium, and Cl is the abbreviation for chlorine.
When the two are combined, you get sodium-chloride, or table salt.
Hope that helped =)
