Solar Cells
.... increase with the orbital radius. When atoms bond together to form
a solid, the electron energy levels merge into bands. In electrical conductors,
these bands are continuous but in insulators and semiconductors there is an
"energy gap", in which no electron orbits can exist, between the inner valence
band and outer conduction band [Book 1]. Valence electrons help to bind together
the atoms in a solid by orbiting 2 adjacent nucleii, while conduction electrons,
being less closely bound to the nucleii, are .....
|
|
Oxygen
.... High-purity oxygen is used also in the metal-
fabrication industries; in liquid form it is of great importance as a propellant
for guided missiles and rockets2.
I have chosen the element "Oxygen" because without Oxygen, human beings
would not be able to live. Oxygen is probably the single most important element
in the world as we know it. With out Oxygen we would not breath, have water, eat
plants.
Oxygen's Electron configuration is 1S2 + 2S2 + 2P4, it's electron dot
symbol is: .
Gaseous ox .....
|
|
Oxygen
.... Wilhelm SCHEELE (1742-86), a Swedish pharmacist and
chemist. It is generally believed that Scheele was the first to isolate oxygen,
but that Priestley, who independently achieved the isolation of oxygen somewhat
later, was the first to publicly announce his findings. The interpretation of
the findings of Priestley and the resultant clarification of the nature of
oxygen as an element was accomplished by the French scientist Antoine-Laurent
LAVOISIER (1743-94). Lavoisier's experimental work, which extend .....
|
|
Ozone
.... the chemical reaction of volatile organic
compounds and nitrogen dioxide, in the atmosphere, in the presence of sunlight.
This reaction is called a photochemical reaction, because sunlight is required.
The product is known as smog. The notorious brownish color of smog is due to
nitrogen dioxide of the mixture. Increased temperature stimulate the reaction,
which is why ozone conditions are worse in the summer. It is an oxidant,
meaning it takes electrons away from other molecules, and disrupts key
str .....
|
|
The Ozone Layer
.... why human regions experience less cooling at night than do dry
regions. Changes in both water and carbon dioxide play an important role in
climate changes. For this reason many scientist have expressed concerns over
the global increase of carbon dioxide in resent decades, largely as a result of
the burring of fossil fuels. In many other factors of the earth’s present
climate remain more or less constant, the carbon dioxide increase should raise
the average temperature at the earth’s surface. Because warm .....
|
|
Pheromones
.... Pheromones are produced by the body
and usually do not smell at all pleasant, whereas perfumes are either
synthesized or extracted from natural products and are employed because of their
pleasant smell.
Scientific research suggests that there are human pheromones for both
the male and the female. Females have a better developed sense of smell and
testing indicates that they are more responsive to male pheromones than the
reverse.
Research over the years has found that the male pheromones belo .....
|
|
Phosphates
.... contain approximately 35% to 75% sodium
triphosphate (Na5P3O10), which serves two purposes. Providing an alkaline
solution (pH 9.0 to 10.5) is necessary for effective cleansing and also to tie
up calcium and magnesium ions found in natural waters and prevent them from
interfering with the cleansing role of the detergent.
Eutrophication is the progressive over-fertilization of water, in which
festering masses of algae's blooms, choking rivers and lakes. Phosphorus
compounds act as a fertilizer .....
|
|
Phosphates In Water Pollution
.... 35% to 75% sodium
triphosphate (Na5P3O10), which serves two purposes. Providing an alkaline
solution (pH 9.0 to 10.5) is necessary for effective cleansing and also to tie
up calcium and magnesium ions found in natural waters and prevent them from
interfering with the cleansing role of the detergent.
Eutrophication is the progressive over-fertilization of water, in which
festering masses of algae's blooms, choking rivers and lakes. Phosphorus
compounds act as a fertilizer for all plant life, whether fre .....
|
|
Photochemical Smog
.... burning of fossil fuels
like gasoline can create another atmospheric pollution problem known as
photochemical smog. Photochemical smog is a condition that develops when primary
pollutants (oxides of nitrogen and volatile organic compounds created from
fossil fuel combustion) interact under the influence of sunlight to produce a
mixture of hundreds of different and hazardous chemicals known as secondary
pollutants. Development of photochemical smog is typically associated with
specific climatic conditions a .....
|
|
UFO's: Seeing Is Believing
.... life.
It seems certain scientists have come up with other hypotheses
concerning UFO's. While all astronomers yearn for a concrete explanation
on UFO's, their beliefs on their origin contrast. Many looking for a more
scientific definition disregard UFO's as nothing more than a mere
misinterpretation of a plane, weather balloon, or meteor. Some have gone
so far as to say that specific witnesses to UFO's have seen nothing more
than a hallucination and "wanted" to see a UFO so their minds adapted that
id .....
|
|
Plutonium
.... for which Neptunium was named. In 1940, at the
University of California at Berkeley, he bombarded a sample of Uranium with
deuterons, the nuclei in atoms of deuterium, transmuting it into plutonium.
Shortly after, Seaborg was able to isolate plutonium 239, an isotope used in
atomic bombs.
Plutonium is a highly dangerous and poisonous element because it rapidly
gives off radiation in the form of alpha particles. Alpha particles, which are
identical to the nucleus of a helium atom, consist of two pr .....
|
|
Quarks
.... quark and an
antiquark, up, down, and strange, while baryons contain three quarks
distinguished by flavours. Each has a charge that is a fraction of that of an
electron. Up and down quarks make up protons and neutrons, and can be observed
in ordinary matter. Strange quarks can be observed in omega-minus and other
short lived subatomic particles which play on part in ordinary matter(1985
Quarks).
The interpretation of quarks as physical entities poses two problems.
First, sometimes two or three identi .....
|
|
Rates Of Reaction
.... of hydrogen as it fisses and it leaves behind a solution
of hydrogen chloride.
The activation energy of a particle is increased with heat. The particles
which have to have the activation energy are those particles which are moving,
in the case of magnesium and hydrochloric acid, it is the hydrochloric acid
particles which have to have the activation energy because they are the ones
that are moving and bombarding the magnesium particles to produce magnesium
chloride.
The rate at which all reactions .....
|
|
A Critique Of The Stanford Experiment
.... booked, after that they were told to put on prison uniforms and
then they were thrown into the slammer (in this case a simulated cellblock
in the basement was used). All of the participants in this experiment at
first were thought to be similar in behavior but after one week, all of
that changed. The prisoners became "passive, dependent, and helpless."
The guards on the other hand were the exact opposite. They became
"aggressive and abusive within the prison, insulting and bullying the
prisoners."
A .....
|
|
The Role Catalysts In Chemical Reactions, Their Importance In Industry, Problems And New Developments
.... and readily give up hydrogen ions, or protons: H+. Protons can be released
from hydrated ions, for example H3O+, but more commonly they are released from
ionisable hydroxyl groups (R-OH) where the O-H bond is broken to produce R-O-
and H+. When the reactant receives protons from an acid it undergoes a
conformational change, (change in shape and configuration), and becomes a
reactive intermediate. The intermediate can then either become an isomer by
returning a proton to the catalyst, or it may undergo a .....
|
|
|
|
