C describes plastics that can be recycled. Thermoplastic can be remolded and reheated after forming, whereas thermoset strengthens when heated
Answer:
100 teragrams of nitrogen per year
Explanation:
Nitrogen fixation in Earth's ecosystems is defined as a process where by nitrogen in air is transformed into ammonia or other related nitrogenous compounds. Generally, atmospheric nitrogen is referred to as molecular dinitrogen and it is a nonreactive compound that is metabolically useless to all but a few microorganisms. This process is vital to life due to the fact that inorganic nitrogen compounds are needed for the biosynthesis of amino acids, protein, and all other nitrogen-containing organic compounds. Thus, the natural rate of nitrogen fixation in Earth's ecosystems is 100 tetragrams of nitrogen per year.
Polar Covalent.
This is because both Calcium (Ca) and Carbon (C) are non metals, thus eliminating the ionic option.
It is polar covalent rather than nonpolar covalent due to the fact that the electrons in a polar covalent bond are shared unequally while those in a nonpolar bond are shared equally.
This can be determined by looking at the amount of valence electrons; if the electrons cancel each other out, it is shared equally. If not, it is shared unequally.
Hope this helps!