20. Describe the differences between the respiratory system of frogs and the respiratory system of humans. Your answer​

Humans breathe exclusively through their lungs, but frogs use their lungs for only part of their respiration. Frog lungs have thinner walls and are almost like balloons. Both species have bronchial tubes leading to the lungs, but human systems are more complicated, with many branching bronchiole

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explanation: bc blah

the relative atomic mass of an element is the mass of one atom of that element, relative to 1/12th of the mass of a  1212c atom. to convert to an absolute mass in kg, it is necessary to multiply by  1.661×10−271.661×10−27.

the relative atomic mass is roughly equal to the number of neutrons, plus the number of protons, in the nucleus of the atom.

for elements with more than one stable isotope (different types of nucleus with different numbers of neutrons but the same number of protons), the quoted mass is usually the average mass, weighted by the relative abundance of the different isotopes.