Select the diagram that correctly illustrates a mixture of oxygen, O2, and nitrogen, N2, gases.

Question

Key
o = atom of one element
black o = atom of a different element

Four boxes, each containing a representation of a substance. 

The top box shows a scattered arrangement of light gray and dark gray circles, roughly evenly distributed. 

The second box displays a more random arrangement of light gray circles amidst various dark gray ones.

The third box illustrates a pattern of a few clusters of light gray circles amongst the dark gray ones, again in a somewhat random fashion.

The bottom box exhibits an arrangement of light gray and dark gray dots scattered throughout the box, with some clusters and a more random distribution overall.

Answer 1

In a mixture of oxygen (O2) and nitrogen (N2) gases, we would expect to see individual molecules of each gas intermixed, but not forming any distinct compounds together. Therefore, you would recognize the presence of both light gray circles (representing O atoms) and dark gray circles (representing N atoms) interspersed without any specific order or fixed ratios.

Based on this description, the diagram that best illustrates a mixture of O2 and N2 gases would be the box that shows a scattered arrangement of light gray and dark gray circles, roughly evenly distributed, which is the top box. The random distribution indicates a mixture, rather than a pattern that suggests a compound.

So, the top box is the correct choice for illustrating a mixture of oxygen and nitrogen gases.