In an isotope of sodium has two extra neutrons what is the atomic weight

Na = 22.989 769 28

Explanation:

For any element can vary the number of neutrons can differ; the same atom differing only by its number of neutrons is called an isotope. The mass number of an element is determined by its proton and neutron number:

Its relative atomic mass or atomic weight of an element is an average of the atomic masses of the element's isotopes. Each isotope's contribution to relative atomic mass is determined by its proportion in the sample.

For instance the relative atomic weight for the element, ...

Na = 22.989 769 28

...this is standard, and can readily be found in entries in the periodic table,but the isotopes atomic mass may be near 25

sheep is a herbivore animal whereas grasshopper belongs to the class chordates but both of them feed on greens.  

if grasshopper and sheep feeding on a pasture land, i do not think both of them will have any impact on each other. however, the number of the species can make difference. since sheep feed on greens, there is a possibility there left no pasture land for the grasshoppers or they may get extinct.