Which term describes the composition of matter shown in figure A

The answer to your question is Element

Explanation:

Element is a substance whose atoms are all the same because of all the atoms

              have the same number of protons, neutrons and, electrons.

Compound is a substance formed when 2 or more atoms combined.

Mixture  is a substance formed by 2 or more different kinds of atoms or

              compounds.

Phase   is a state of matter like solid, liquid or gas.

According to the definitions, we conclude that the figure is an Element.

n2(g) + 3h2-> 2nh3(g)   this is the balanced equation

note the mole ratio between n2, h2 and nh3.   it is 1 : 3 : 2   this will be important.

moles n2 present = 28.0 g n2 x 1 mole n2/28 g = 1 mole n2 present

moles h2 present = 25.0 g h2 x 1 mole h2/2 g = 12.5 moles h2 present

based on mole ratio, n2 is limiting in this situation because there is more than enough h2 but not enough n2.

moles nh3 that can be produced = 1 mole n2 x 2 moles nh3/mole n2 = 2 moles nh3 can be produced

grams of nh3 that can be produced = 2 moles nh3 x 17 g/mole = 34 grams of nh3 can be produced

note:   the key to this problem is recognizing that n2 is limiting, and therefore limits how much nh3 can be produced.

answer

the ions in solute supperate from eachouthere