An ionic<span> crystal consists of </span>ions<span> bound together by electrostatic attraction. The arrangement of </span>ions<span> in a regular, geometric structure is called a crystal lattice. Examples of such </span>crystals<span> are the alkali halides, which include: potassium fluoride </span>
For pressure and volume, as the volume goes up, meaning the container gets bigger, the pressure would go down. There would be more room in the container, so there would be less collisions between the molecules themselves and between the molecules and the container. This makes them inversely proportional.
For pressure and temperature, as the pressure goes up, there are more collisions, so the particles move faster. Temperature is the speed of the particles, so, since both pressure and temperature would go up at the same time, they are directly proportional.
For volume and temperature, this is similar to the PV relationship. As volume increases, there are less collisions between the particles. This means that the particles are going to move slower. Therefore, as volume goes up, temperature goes down, so they are inversely proportional.
Sorry this is super long, but I hope it fully explains the question for you! ☺
When scientist find new species that may have to change classification systems in order to accommodate them. DNA sequencing has also let us find out more about evolutionary relationships. The more recent the common ancestor, the more closely related the two species are.