When the snow melts, where does the white go?

2011-05-07T12:30:00.001-07:00

Snow isn't really white to begin with. Snow is frozen water and is not transparent; it's actually translucent. This means that the light photons don't pass right through the material in a direct path -- the material's particles change the light's direction. This happens because the distances between some atoms in the ice's molecular structure are close to the height of light wavelengths, which means the light photons will interact with the structures. The result is that the light photon's path is altered and it exits the ice in a different direction than it entered the ice.

Snow is a whole bunch of individual ice crystals arranged together. Basically, all the crystals bounce the light all around so that it comes right back out of the snow pile. It does the same thing to all the different light frequencies, so all colors of light are bounced back out. The "color" of all the frequencies in the visible spectrum combined in equal measure is white, so this is the color we see in snow, while it's not the color we see in the individual ice crystals that form snow.

What Is Chemistry?

2011-04-30T11:19:00.000-07:00

If you look 'chemistry' up in Webster's Dictionary, you'll see:

"chem·is·try n., pl. -tries. 1. the science that systematically studies the composition, properties, and activity of organic and inorganic substances and various elementary forms of matter. 2. chemical properties, reactions, phenomena, etc.:

My definition is the short and sweet, "scientific study of matter, its properties, and interactions with other matter and with energy". An important point to remember is that chemistry is a science, which means its procedures are systematic and reproducible and its hypotheses are tested using the scientific method. Chemists, scientists who study chemistry, examine the properties and composition of matter and the interactions between substances. Chemistry is closely related to physics and to biology. As is true for other sciences, mathematics is an essential tool for the study of chemistry.

Chemistry is the science of the materials that make up our physical world. No one person could expect to master all aspects of such a vast field, so it has been found convenient to divide the subject into smaller areas. For example:

Organic chemists study compounds of carbon. Atoms of this element can form stable chains and rings, giving rise to very large numbers of natural and synthetic compounds.
Biochemists concern themselves with the chemistry of the living world.
Inorganic chemists are interested in all elements, but particularly in metals, and are often involved in the preparation of new catalysts.
Physical chemists study the structures of materials, and rates and energies of chemical reactions.
Theoretical chemists with the use of mathematics and computational techniques derive unifying concepts to explain chemical behavior.
Analytical chemists develop test procedures to determine the identity, composition and purity of chemicals and materials. New analytical procedures often discover the presence of previously unknown compounds.

Although the list may seem pretty comprehensive, in fact there are a whole lot more Chemistry disciplines, for example,

Astrochemistry - study of elements, compounds and chemical reactions in space
Atmospheric Chemistry - study of planetary atmosphere
Chemical Engineering - study of the conversion of raw materials into more useful forms
Chemical Biology - application of chemical techniques to the manipulation of biological systems
Chemo-informatics - application of information techniques to chemical problems
Crystallography - the study of the arrangement of atoms in solids
Environmental Chemistry - the study of chemistry occurrring in natural places
Flavour Chemistry - the study of the chemicals and systems involved in flavour
Geochemistry - study of the chemical composition of the Earth and other planets
Green Chemistry - study of elimination or reduction in the use and generation of hazardous substances
Immunohistochemistry - study of the localization of proteins in tissue cells
Immunochemistry - study of the chemicals and reactions of the immune system
Industrial Chemistry - study the optimization of chemical processes
Materials Science - study of the relationship between molecular structure and macroscopic properties
Mathematical Chemistry - applications of mathematics to chemistry problems
Medicinal Chemistry - study of the design, synthesis and development of pharmaceutical drugs
Molecular Biology - study of chemical interactions within a cell
Nanotechnology - study of the control of matter at the atomic and molecular scale
Natural Product Chemistry - the study of natural products found in nature
Oenology - the study of the chemistry of wine and winemaking
Neurochemistry - the study of neurochemicals
Organometallic Chemistry - study of chemical compounds containing bonds between carbon and metal atoms
Petrochemistry - study of the transformation of crude oil and natural gas into useful products
Pharmacology - study of drug action
Photochemistry - study of the interactions between atoms, molecules and electromagnetic radiation
Physical Organic Chemistry - study of interrelationships between structure and reactivity in organic molecules
Phytochemistry - study of chemicals derived from plants
Polymer (Macromolecular) Chemistry - study of the synthesis and properties of polymers (macromolecules)
Quantum Chemistry - application of quantum mechanics to chemistry
Solid-State Chemistry - study of synthesis,structure and physical properties of solids
Sonochemistry - study of the effect of sonic waves and wave properties on chemical systems
Supramolecular Chemistry - study of the weaker, non-covalent interactions between molecules
Surface Chemistry - study of the interactions occurring at the interface of two phases
Theoretical Chemistry - study of chemistry from fundamental theoretical reasoning

One of the main functions of the chemist is to rearrange the atoms of known substances to produce new products. For example, chemists have developed previously unknown synthetic fibres such as Kevlar, which has desirable qualitites not found in natural fibres. The development of plastics such as polyethylene and Teflon has resulted in the production of many new items previously unavailable because no natural product could do the job. New alloys and special fuels allow us to travel in outer space. Chemists have helped to develop these and thousands of other new and useful products.
Chemistry is involved in almost everything with which we come in contact. The life processes of all organisms involve chemical changes. Chemists play a key role in the development of drugs, which are helping to cure and alleviate diseases and prolong life span. Chemists are involved in biochemistry and genetic engineering . For example, there is much interest in producing new bacterial strains, which can synthesize useful products such as human insulin or interferon. Chemists are also at the forefront of developing fields such as nanotechnology. They are actively involved in environmental issues and are helping to tap new sources of energy to replace the earth's finite reserves of petroleum.

Your textbook probably defines Chemistry as the study of matter, we think of Chemistry as the study of life, the universe and everything.

Your whole, entire body, is one big chemical factory. Every breath you take, every move you make, and every piece of food you digest, involves chemical reactions.
Everything you see, touch, smell and taste during your life is made up of atoms. Even the way you perceive the world through your senses involves chemical reactions. And, in the fullness of time, when you die, a whole array of chemical processes takes place during decay.
Indeed, the universe itself is just one big chemical factory, rearranging atoms and sub-atomic particles to produce elements and compounds. Planets are made up of rocks which are just an interesting arrangement of compounds, and an atmosphere is just a mixture of compounds separated by distance. Even the vast reaches of "near vacuum" between stars and planets, and between galaxies, is just a huge volume of sparsely distributed molecules.
Thus, with its broad scope, chemistry offers an exciting array of intellectual adventures and opportunities. Basically, if you have an interest in any sort of science at all, there is a Chemistry discipline that will cover it!
Best of Luck…

Chemical Sciences

When the snow melts, where does the white go?

What Is Chemistry?