Which organ is responsible for absorbing nutrients like nitrogen. root, leaf, stem

Roots

Explanation:

Nitrogen fixation is important for plants, and it does so underneath the soil through the roots. Roots are what take in nutrients.

Attached is a helpful picture. You can see the channels for taking in nitrogen compounds, which are in the roots!

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.

d. groundwater flows through the subsoil and deposits minerals.