Arrange these molecules in order of decreasing mass: C6H14 , NO2 , Fe2O3 , and CaCO

The decreasing order of the mass of the molecules are:

Fe2O3>C6H14>CaCO>NO2

Explanation:

Let us calculate the atomic mass of the molecules given:

C6H14                                     Atomic mass of 1 carbon atom =12.01 amu

so, 6*12+1*14                                           Atomic mass of  hydrogen=1.007

= 86 g/mol

Atomic mass of NO2

  = 14+ (2*15.9)

   = 14+ 31.8

     = 45.8 g/mol

Atomic mass of Fe203

( 2*55.845)+ (3*15.9)

= 159.69 g/mol

Atomic mass of CaCO

40.07+12.0107+15.99

= 68.07g/mol

The decreasing order of the mass of the molecules are:

Fe2O3>C6H14>CaCO>NO2

answer; (d) constructive and destructive force;

answer is: c. the experiment shows that the red substance experienced a chemical change.

this is chemical change (chemical reaction), because two new substances are formed (metalig liquid and gas), the atoms are rearranged and the reaction is followed by an energy change.

this is example of chemical decomposition.

chemical decomposition (analysis) is the separation of a single chemical compound into its two or more elemental parts or to simpler compounds.  

chemical decomposition is opposite of chemical synthesis.