The photo below shows a picture of an agate stone. Jack, who picked up the stone on the Lake Superior shoreline and polished it, insists that agate is a chemical compound. Ellen argues that it cannot be a compound. Discuss the relative merits of their positions.

Video transcript

Welcome back everyone. The image below shows a picture of an Opal Stone student. A claims that the stone is a chemical compound and student B claims that it cannot be a compound who is correct. And we need to explain why. Below, we observe this Opal stone and we can observe that it has has a range of various colors ranging from blue turquoise green and to a brownish red making up this stone. Let's begin by defining what a compound is defined as. And so a compound recall describes a pure substance and this pure substance can contain more than one type of atom so containing multiple atoms which have consistent properties. Some of those properties can include things like density, its color and o odor of this compound. And not only should it have consistent properties, but it should have consistent composition. And by that, what we mean is the way that the elements which make up a certain compound are combined and bonded together should always be the same no matter the size of your sample of a certain compound or the source. So we'll note that it, that consistent composition means a constant ratio of elements that make up the compound. Now with all of this in mind, as far as this definition of a chemical compound, when we observe this Opal stone, as we noted earlier, it has multiple colors. So these multiple colors that are present in this Opal stone indicates that Opal has a complex structure and a complex composition. So there are likely trace elements and compounds that make up this Opal stone. And if we were to have multiple samples of an Opal stone, each sample will have varying properties and varying compositions. And so therefore, because the complex structure and composition will vary between samples of opal, it is therefore not going to be a compound recall that Opal is considered a mineral oid and it's best described as a complex mixture. So for the final answer to explain this prompt, we're going to say that student B is correct. And our explanation for why is because Opal does not have a constant composition. It is a complex mixture and can contain some impurities as well as varying properties between different samples of, of Opal. And so this will explain this prompt as our final answer. I hope that this made sense and let us know if you have any questions.