How does a straight-chain alkane that has five carbon atoms differ from a cycloalkane that has five carbon atoms?
The straight-chain alkane has at least one double or triple bond, but the cycloalkane has only single bonds.
The straight-chain alkane has only single bonds, but the cycloalkane has at least one double or triple bond.
The straight-chain alkane has two more hydrogen atoms than the cycloalkane.
The straight-chain alkane has two fewer hydrogen atoms than the cycloalkane.

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.

i think it is true since you can test the answer and can use observations to complete it.

un recipient conține 6,4 moli de gaz. gazul hidrogen reprezintă 25% din totalul kilometrilor din container. în cazul în care presiunea totală este de 1.24 atm ceea ce este