Which is true of a molecule?

What is the mass of each element in a 324.8 sample of co2

The table compares the number of electrons in two unknown neutral atoms. comparison of electrons atom number of electrons a 10 d 11 use this information to determine the number of valence electrons in the atoms. which of the following correctly compares the stability of the two atoms? both are unreactive. both are highly reactive. a is unreactive and d is reactive. a is reactive and d is unreactive.

Which characteristics can be used to differentiate star systems? check all that apply.