States of matter and separating mixtures - Intro

Tap water, orange juice, the air in this room and the ink in your pen are all mixtures. Chemistry sorts any stuff it meets in two ways. First, by the state it is in. Then, by whether it is one substance or several mixed together. This chapter builds the particle picture behind the first, then uses it to pull mixtures apart again. Later chapters, from making a salt to cleaning drinking water, expect you to know those methods already.

Most of this chapter is for every student, Foundation and Higher, combined science and separate chemistry alike. Where a video is not for everyone, it is flagged as it comes up.

If states of matter are new to you, start with The three states of matter and the particle model. It gives each state its own way of moving, because a common slip is giving a solid's movement to a liquid. The limits of the simple particle model comes next, and its title says Higher. If you sit the Foundation paper, you can skip it. That one is also left out of one board's specification, so check yours before you spend time on it. If a question hands you a mixture and asks how to get one thing out, go to Mixtures, and choosing a separation technique. A common slip is trying to filter or distil a compound, so that video starts by checking whether you have a mixture at all. Pure substances, and spotting an impurity from a melting point turns a table of temperatures into a verdict. On one purity question, fewer than a quarter of students gained a mark. Formulations is not on every specification. Where it is, the usual gap is calling a formulation a mixture and stopping there. Chromatography and Rf values is on every specification at both tiers, and the common slip in it is dividing the wrong way round. If your exam is close, that is the video to press first. Every video can be searched by its name or by its code. The quickest way is the scholafly.com website, which indexes every video in every subject.

Next in the chapter is The three states of matter and the particle model. Hopefully that's next in your feed, but if not, search for ScholaFly C H oh three, oh one.

Every other video is on scholafly.com too, easy to search by video code or by keyword. Whatever you're revising, go there and have a look, or, watch the next video.