It's either 1 or 4 (hfjsjhsjsjwjje)
Answer:
Index Fossils
Explanation:
Index fossils are used by scientists to help them figure out the dating of discovered fossils or the correlation. They are also very known to appear in a (very) certain/specific age range.
Hope this Helps!
It is a semiconductor. A semiconductor can allow a bit of energy to flow through. It is also a metalloid. Hope this helps! :)