the
greatest English novelist and one of the
most famous English women who ever
lived.
The most ancient Uzbek oral literary works are over 200 epic
poems, many legends, epic songs performed by folk poets -
bakhshi.
Heroes of folklore
struggle with
hostile forces - evil
spirits, dragons.
The oldest cycle of
epic poems Ker-
ogly and the poem
Alpamysh were
written around the
10th century.
PROTEINS AND PEPTITS
CATALYSTS AND
REACTION
CONDITIONS
BIOCTIVE
COMPOUNDS AND
BIOCHEMISTRY
It is suggested that the topic
Reading chemical formulas
be read before undertaking this topic. Chemists
have a special shorthand way of writing the names of chemicals and how they behave in chemical
r
eactions.
or example, water has the formula H
2
O and when aluminium combines with oxygen in the air to corrode,
chemists
write
the
equation:
- 4 Al + 3 O
2
2 Al
2
O
3
for the reaction.
This topic will help you to read what chemists mean when they write chemical equations.
Formulas
and
chemical
reactions
Chemists have formulas or shorthand names for all atoms, ions, molecules and ionic salts known. These
formulas list the types of atoms and number of each atom present in a substance.
During chemical reactions, substances are broken down and new substances formed. Once a chemist has
determined which substances are involved in a reaction their formulas can be determined using the rules of
valency and covalency. (See the related topics for more information on valency and covalency.) The
formula of a substance is set by these rules and is always the same. Water always has the formula H
2
O
and never varies!
Modern chemistry
Molou Kouassi Yves Guillaume, Timotou Adeyole, Coulibaly
Souleymane, Camara Tchambaga Etienne, Kablan Ahmont Landry
Claude, Coulibali Siomenan, Sissouma Drissa
Pages: 106-112 Published Online: Nov. 4, 2022
)
Frohlich Georg
Pages: 98-105 Published Online: Sep. 28, 2022
Dawit Darcha, Abebe Desalegne, Biruk Bezabeh Yimam, Turunesh
Debela Jufar
Pages: 93-97 Published
Alchemy was developed in Europe in the medieval age and it founded the origin
of modern chemistry [1]. The brilliantly shining color and the almost perfect
chemical inertness of gold has attracted men and women as a symbol of eternal
power and beauty. It is therefore reasonable that so many people dreamed to
produce gold artificially. Even Newton was deeply involved in the chemical
synthesis of gold [2].
Due to this history, gold has long been neglected as an element of valuable
functions. For example, gold was regarded to be almost inactive as a catalyst and
was indeed much less active than palladium and platinum [3]. During the course of
synthesizing mixed oxides of gold with base transition metals, I found in 1982 that
when gold was coprecipitated with 3d transition metals and calcined at
temperatures above 570 K, the mixed oxides exhibit high catalytic activities for CO
oxidation even at a temperature as low as 200 K [4]. Later, the mixed oxides were
proved by Iijima with a transmission electron microscopy to be composed of
hemispherical ultrafine particles of gold attached strongly to the base metal oxide
supports [5]. The surprisingly high catalytic activities generated by nanoparticulate
gold were introduced as one of the typical examples which could demonstrate the
benefit of nanoscience and technology [6].
This chapter focuses on recent attempts which demonstrate how size control
can turn inert gold into excellent catalyst. There have already been
published many general reviews on gold catalysts in a wider scope [7–12].
The global market sales of catalysts amount to 8.9 billion US dollars in 2003
[13]. The market is almost equally shared by four sectors: petroleum
refinery, chemical production, polymer production, and environmental
maintenance. In the whole market of chemical catalysts, oxidation comes
after polymerization (49%) and occupies 18%, exceeding the shares of organic
synthesis (15%) and synthesis gas production (10%). Gold is expected to make
significant contributions to oxidation processes, because it can often exhibit
better catalytic performances than palladium and platinum in selective
oxidation of hydrocarbons and organic oxygenates [14,15].
Gold has recently been launched as a break in R&D activities. In both the
13th International Congress on Catalysis, Paris, July 2004 and the 5th World
Conference on Oxidation Catalysis, Sapporo, September 2005, papers dealing
with Au occupied about 9%, which exceeded that of Pt catalysts, 4% in the
case of 5WCOC. The number of scientific papers dealing with Au catalysts has
recently grown exponentially as shown in Figure
Solving Sciantific
Problems
Divide the class into groups, and give each group a basic set of
supplies (this could include paper, tape, a paper towel roll,
rubber bands, ponytail holders, paper plates, etc.), as well as
one egg. Tell them that their job is to collectively design and
create a holder for the egg that will be dropped from a
substantial height. The goal is to create a holder that will
protect the egg as much as possible. Give students time to work
on their egg holders. When they are done, drop them and see
what happens. You can use this to talk about physics and/or
engineering, as well as how scientists approach a problem.
Materials: Eggs, random supplies as desired, a high place from
which to drop eggs, and a place that can get eggs on it
Divide the class into small groups. Give each group the same picture
of a simple creature that lives in the water near the shore. For this
activity, you will present a series of scenarios, one at a time. This
could be things like a change in climate, the introduction of a new
predator, or a rival species that adapted to better access to the
food supply. For each scenario, groups will have a few minutes to
decide how their species will adapt in order to best survive this new
change. Continue this for several rounds. When you're done, have
the groups show off the adaptations and see how much their species
changed. Did it move to land, or learn to fly? Did it become more
predatory, or start reproducing faster, or become camouflaged? Talk
about adaptation and evolution with the class.
Materials: Images of starting creature, list of scenarios, writing or
drawing supplies as desired
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