Ordovician-Silurian
Permian-Triassic
End Triassic
Cretaceous-Tertiary
The Late Devonian.
If you go back and reach the text, you may find the passage, "Which species did we lose during this extinction (Late Devonian)? About 20% of all animal families and 70-80% of all animal species were lost. Major victims included the following:
....
- Jawless fish"
Answer:
To determine the value of atmospheric pressure, we can use the concept of hydrostatic pressure. By comparing the lengths of the air column in the capillary tube when held horizontally and vertically, we can equate the pressure difference to the difference in height of the mercury column. Using the given values and the density of mercury, we can calculate the atmospheric pressure.