What are covalent bonds

Can anyone (a-level) a student was analysing a carbonate compound, mco3, containing an unknown group 2 metal, m. the student carried out thermal decomposition on 0.730g of the carbonate and measured the volume of gas produced. mco3 (s) mo (s) + co2 (g) the student collected and measured 120cm3 of carbon dioxide. 1 mol of carbon dioxide occupies 24 000 cm3 under these conditions. calculate the molar mass of the group 2 carbonate and hence deduce the identity of the group 2 metal, m.

Why do cells appear different in distilled water than they do in 10% salt water?

Jose and eric were given four samples in lab. the results of their analysis are shown in the table. based on the data they collected, which sample is most likely a metal?