The combustion of methane, CH4, releases 890.4 kJ/mol. That is, when one mole of methane is burned, 890.4 kJ are given off to the surroundings. This means that the products have 890.4 kJ less than the reactants.
Answer : The volume of liquid is 420 mL.
Explanation :
Density : The mass per unit volume of a substance is known as density.
Formula used:

As we are given:
Density of mercury = 13.5 g/mL
Mass = 12.5 pounds
First we have to convert mass of sample from pound to gram.
Conversion used:
As, 1 pound = 453.6 g
So, 12.5 pounds = 453.6 × 12.5 g = 5670 g
Now we have to calculate the volume of liquid.

Now putting all the given values in this formula, we get:

Volume = 420 mL
Therefore, the volume of liquid is 420 mL.
I think answer is
C. Something that can be observed or measured while changing the identity of the substance
Answer:
C. It does not emit electromagnetic radiation.
Explanation:
Right now, Dark Matter is only a theory. Scientist proposed this to counter some of the strange phenomenon with matter in space.
Scientists know little about dark matter. Some say it's one of the driving forces of the universe. Currently, scientists have no way of measuring or identifying dark matter.
Answer:
A student's name paired with the sport that they play.
Explanation: