I believe that the answer is D.
I hope this helps. :)
C. a burning candle
all the other choices are physical changes
Formula:

Given:
Density=3.4
Volume=500.0
Plug them into the formula:
Final answer: 1700g
Answer:
Ethane would have a higher boiling point.
Explanation:
In this case, for the lewis structures, we have to keep in mind that all atoms must have <u>8 electrons</u> (except hydrogen). Additionally, each carbon would have <u>4 valence electrons</u>, with this in mind, for methane we have to put the hydrogens around the carbon, and with this structure, we will have 8 electrons for the carbon. In ethane, we will have a bond between the carbons, therefore we have to put three hydrogens around each carbon to obtain 8 electrons for each carbon.
Now, the main difference between methane and ethane is an <u>additional carbon</u>. In ethane, we have an additional carbon, therefore due to this additional carbon, we will have <u>more area of interaction</u> for ethane. If we have more area of interaction we have to give <u>more energy</u> to the molecule to convert from liquid to gas, so, the ethane will have a higher boiling point.
I hope it helps!
Explanation:
The gravitational force between two 50kg objects could be less than the gravitational force between a 50kg and a 5kg object if the two 50kg objects are much farther apart.