Trilobites are extinct marine invertebrates. Scientists found a trilobite fossil in layer 5, shown here. Fossils in which layer are likely to be slightly older than
this trilobite fossil?

What is thought to have caused the mass extinction at the end of the cretaceous period?

How does a gymnosperm prevent itself from pollinating the same tree

You are working in the lab and are working with the same element but with varying isotopes of the element. you are working with c-11, c-13, c-14, and c-15. what is the average atomic mass of this element? (use periodic table) a- 12 b-15 c-14 d-13