Answer:
There is no actual way that the mantle could be...'exposed' or 'seen'. But scientists have managed to find multiple ways to analyze the mantle and it's actual existence by using multiple devices. The mantle is basically a 2,900 kilometers (1,802 miles) thick blocks of rocks and minerals underneath the crust(or the surface of the earth) , and makes up a whopping 84% of Earth's total volume.
Answer:
Radioisotopes are radioactive isotopes of an element
Explanation: Radioactive isotopes are detected by: photographic film.
a cloud or bubble chamber.
a liquid scintillation detector.
a Geiger-Muller counter.
The periodic table only accounts for elements. It does not account for compounds, such as water.
I'm assuming that you want us to tell you what organism does these things. So it would be a plant.
It is definitely not a primary source: this would be a book itself.
Now, is it a tertiary source? I don't think so: the author of the review should have read the book and should only be referring to this book in the review.
I think it's a secondary source.
