Question 2 here are four sketches of pure substances. each sketch is drawn as if a sample of the substance were under a microscope so powerful that individual atoms could be seen. decide whether each sketch shows a sample of an element, a compound, or a mixture.

The image with the four sketches that accompany this question was obtained in internet and is attached.

Explanation:

The first picture shows substance X as a matter composed by particles of one type. Every particle consists of two white balls bonded to one red ball, sketching a compound formed by two "white atoms" and one "red atom". So, this sketch shows a sample of a compound.

The second picture shows substance Y formed by two different kind of particles. One type of particles are two white balls bonded, sketching a molecule of two equal atoms, i.e. an element in the form of a diatomic molecules of a single element (likely a gas). The other type of particles are two white balls bonded to one red ball (just as in the first picture). This sketch, then, shows the mixture of one element and one compound. Thus, this is a mixture.

The third picture shows substance W formed by one type of particles: groups of two identical white balls. So, every pair of white ball sketchs a diatomic molecule, which means that this is an element (think, for example, in H₂ or O₂).

The fourth picture shows substance Z formed by groups of particles of the same type: two red balls bonded to two white balls. So, every group of these particles represents identical compounds, making this a compound and not a mixture.