What do solids have the lowest amount of

The sheets of graphite are held together by only weak London forces! Metallic solids— Made up of metal atoms that are held together by metallic bonds. Characterized by high melting points, can range from soft and malleable to very hard, and are good conductors of electricity. These atoms, ions, or molecules are called lattice points and are typically visualized as round spheres. See Below.

Figure 1: Two possible arrangements for identical atoms in a 2-D structure. Stacking the two dimensional layers on top of each other creates a three dimensional lattice point arrangement represented by a unit cell. A unit cell is the smallest collectionof lattice points that can be repeated to create the crystalline solid.

The solid can be envisioned as the result of the stacking a great number of unit cells together. Primitive Simple Cubic Structure Placing a second square array layer directly over a first square array layer forms a "simple cubic" structure.

This packing arrangement is often symbolized as "AA The coordination number of each lattice point is six. This becomes apparent when inspecting part of an adjacent unit cell Figure 3b. The considerable space shown between the spheres in Figures 3b is misleading: lattice points in solids touch as shown in Figure 3c.

For example, the distance between the centers of two adjacent metal atoms is equal to the sum of their radii. Refer again to Figure 3b and imagine the adjacent atoms are touching. Reapplication of the theorem to another right triangle created by an edge, a face diagonal, and the body diagonal allows for the determination of the body diagonal as a function of r Figure 4b. Few metals adopt the simple cubic structure because of inefficient use of space.

The density of a crystalline solid is related to its "percent packing efficiency". Body Centered Cubic bcc Structure A more efficiently packed cubic structure is the "body-centered cubic" bcc. The first layer of a square array is expanded slightly in all directions.

Then, the second layer is shifted so its spheres nestle in the spaces of the first layer Figures 5a, b. This repeating order of the layers is often symbolized as "ABA Like Figure 3b, the considerable space shown between the spheres in Figure 5b is misleading: spheres are closely packed in bcc solids and touch along the body diagonal. The coordination number for an atom in the bcc structure is eight. How many total atoms are there in the unit cell for a bcc structure?

Draw a diagonal line connecting the three atoms marked with an "x" in Figure 5b. In the solid state, the individual particles of a substance are in fixed positions with respect to each other because there is not enough thermal energy to overcome the intermolecular interactions between the particles.

As a result, solids have a definite shape and volume. Most solids are hard, but some like waxes are relatively soft. Many solids composed of ions can also be quite brittle. Solids usually have their constituent particles arranged in a regular, three-dimensional array of alternating positive and negative ions called a crystal. Glass is one example of an amorphous solid. If the particles of a substance have enough energy to partially overcome intermolecular interactions, then the particles can move about each other while remaining in contact.

This describes the liquid state. In a liquid, the particles are still in close contact, so liquids have a definite volume. However, because the particles can move about each other rather freely, a liquid has no definite shape and takes a shape dictated by its container. If the particles of a substance have enough energy to completely overcome intermolecular interactions, then the particles can separate from each other and move about randomly in space.

Like liquids, gases have no definite shape, but unlike solids and liquids, gases have no definite volume either. The change from solid to liquid usually does not significantly change the volume of a substance. However, the change from a liquid to a gas significantly increases the volume of a substance, by a factor of 1, or more. Earth is the only known body in our solar system that has liquid water existing freely on its surface.

That is a good thing because life on Earth would not be possible without the presence of liquid water. Water has several properties that make it a unique substance among substances. It is an excellent solvent; it dissolves many other substances and allows those substances to react when in solution. In fact, water is sometimes called the universal solvent because of this ability.

Though a liquid at normal temperatures, water molecules experience a relatively strong intermolecular interaction that allows them to maintain the liquid phase at higher temperatures than expected. Unlike most substances, the solid form of water is less dense than its liquid form, which allows ice to float on water. The most energetically favorable configuration of H 2 O molecules is one in which each molecule is hydrogen-bonded to four neighboring molecules. Very close together. Slightly further apart than a solid.

Slightly less than the solid. Very much further apart than a solid or liquid. Very much less than the solid or liquid.