40. Because sodium chloride is NaCl
Iodine and Calcium is the correct answer
Yes. Stars use fusion to create nuclear energy, which is what makes them "alive". The older they are, the "bigger" the element in them is. Hydrogen turns into Helium, and when hydrogen is used up, the helium starts fusing into bigger elements. it stops at iron however. Once stars start fusing silicon to iron, it is doomed because it takes more energy than it gives off.
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.