I think answer is
C. Something that can be observed or measured while changing the identity of the substance
<span>1.61 × 1023 Multiply by 26.8 to get the answer.161.33 x 10 ^23 </span>
Answer: Although the best-known cause of a mass extinction is the asteroid impact that killed off the non-avian dinosaurs, in fact, volcanic activity seems to have wreaked much more havoc on Earth's biota. Volcanic activity is implicated in at least four mass extinctions, while an asteroid is a suspect in just one. Examples, of mass extinctions are Permian extinction of marine species, and Cretaceous extinction of various species, including dinosaurs.
There are two ways to liquefy a gas:
-- Increase the pressure on it.
-- Lower its temperature.
The liquefication is faster and easier if you do both.
