Solids are the fourth fundamental state of matter, with molecules closely packed together and the least kinetic energy. Because of this, solids exhibit structural rigidity and resistance to forces applied to their surface. What makes solids so stable? Here are some answers. The most important characteristics of solids:
Crystals are solids
Most solids consist of many individual atoms or molecules joined together by a bonding force called a ‘grain boundary.’ The arrangement of the electrons within an atom is characteristic of a solid, and determines its physical and chemical properties. Crystals are composed of both point and extended defects. Point defects are those that are found in a single crystal, while extended defects are those that are present in a mixture of several atoms.
Metals are malleable
When a metal is heated or cooled, its grain boundaries collapse, making it more malleable. For example, zinc remains brittle at lower temperatures, but becomes malleable above 300 degrees. Another way to make metals more malleable is to alloy them. Sterling silver and brass are less malleable than copper, so they are both alloyed. However, it is still possible to shape metals, such as aluminum and copper, without alloying them with other elements.
Mercury is a solid
Mercury is a solid sphere with a large iron-rich core that makes up nearly 80% of its mass and volume. This might explain its high density. Mercury is also named after the Roman god of travelers and merchants. Mercury’s day lasts for two Mercurian years, or about six Earth months. The planet’s atmosphere is largely composed of hydrogen, oxygen, potassium, and sodium. Its temperatures are similar to Earth, and its atmosphere is thin.
Molecular bonds hold solids together
There are three types of solids, ionic, metallic, and covalent network solids. All three solids contain individual molecules that are held together by hydrogen bonds. These forces are weaker than chemical bonds and create softer solids. Molecular solids are generally very soft and have low melting points. A molecule solid’s melting point is determined by its specific composition. Examples of solids made from atoms that are bound together by hydrogen bonds are ice and dry ice.
The shape of liquid droplets is a result of the surface tension of the solid. Droplets of water are deformed easily and are drawn into a spherical shape due to an imbalance in the cohesive forces of the surface layer. Otherwise, all liquids would be spherical. The spherical shape minimizes wall tension of the surface layer. So, how do we calculate the surface tension of a solid?
Density of solids
Density is a measure of how much mass a solid has relative to its volume. Generally, solids have a higher density than liquids, and liquids have a lower density than solids. Solids have less mass per unit volume than liquids and gases, but this does not always hold true. The sponge, for example, has a low density and floats on water. When you change a solid from a liquid state to a solid again, its volume will increase, while its mass will decrease.