Jawless fish and ocean reefs were devastated by which extinction?

late devonian

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"

  the grams     of oxygen gas   that can be produced     is 20.6   grams of o₂

calculation

2liclo₃ →   2 licl + 3 o₂

step 1:   find the moles of liclo₃

moles = mass÷ molar mass

from periodic table the molar mass of liclo₃ =6.9 +35.5   +(16 x3) =90.4 g/mol

moles=38.7 g÷90.4 g/mol=0.4281   moles

step 2:   use the   mole ratio   to calculate the moles of o2

from equation above, liclo₃: o₂   is 2: 3  

therefore the moles of   o₂=0.4281 moles x3/2 =0.6422   moles

step 3: find mass   of o₂

mass= moles x molar mass

from periodic table the   molar mass of   o₂ = 16 x2= 32 g/mol

mass=0.6422   moles   x   32 g/mol = 20.6 grams of o₂

the five characteristics of adolescence are biological growth and development, and undefined status, increased decision making, increased pressure and the search of self.