Matter & Energy


Order in Matter

Matter is composed of atoms or groups of atoms called molecules. The arrangement of particles in a material depends on the physical state of the substance. In a solid, particles form a compact structure that resists flow. Particles in a liquid have more energy than those in a solid. They can flow past one another, but they remain close. Particles in a gas have the most energy. They move rapidly and are separated from one another by relatively large distances.

Popular posts from this blog

Converting Food to Usable Energy

Cellular respiration is a complex series of chemical reactions that harvests the energy trapped in the bonds of glucose sugar molecules and converts it into a chemical form that can be stored for later use. Humans and other animals obtain glucose sugar molecules from food, such as the fruits and grains shown here, while plants create glucose sugars in the process of photosynthesis. Essential to the survival of most organisms on Earth, cellular respiration yields the energy that makes our bodies function properly.
Read more

Electrical Conductor

. Electrical Conductor, any material that offers little resistance to the flow of an electric current. The difference between a conductor and an insulator, which is a poor conductor of electricity or heat , is one of degree rather than kind, because all substances conduct electricity to some extent. A good conductor of electricity, such as silver or copper , may have a conductivity a billion or more times as great as the conductivity of a good insulator, such as glass or mica. A phenomenon known as superconductivity is observed when certain substances are cooled to a point near absolute zero , at which point their conductivity becomes almost infinite. In solid conductors the electric current is carried by the movement of electrons; in solutions and gases , the electric current is carried by ions.
Read more

Chloroform

. Chloroform, name given to trichloromethane because of its supposed relation to formic acid. A colorless liquid, half again as dense as water and of about the same viscosity, chloroform has a heavy, etherlike odor and a burning sweetness of taste, being about 40 times as sweet as cane sugar. It is almost insoluble in water, but it is freely miscible with organic solvents and is an important solvent for gums, resins, fats, elements such as sulfur and iodine, and a wide variety of organic compounds. Chloroform may be prepared by the chlorination of ethyl alcohol or of methane, or by the action of iron and acid on carbon tetrachloride; the latter is the principal industrial method in current use. Chloroform was first prepared in 1831 and was first used as an anesthetic in 1847 in one of the earliest experiments on surgical anesthesia . In the presence of light, however, it tends to decompose, yielding the highly poisonous compound phosgene. Even when pure, it causes fatal cardiac paralys...
Read more