Chemistry, from the ancient Egyptian, literally means “earth”. Chemistry is the science concerned with the composition, structure, and properties of matter. Also, chemistry concerns itself with the changes matter undergoes during chemical reactions. Modern chemistry evolved out of alchemy following the chemical revolution of 1773.
Dynamic vulcanization of natural rubber (RSS) was studied. The effect of methods of vulcanization, i.e. sulphur, sulphurless and peroxide on mechanical, rheological properties, thermal ageing and weathering tests were investigated. Swelling behavior of when using sulphur, sulphurless and peroxide were investigated. Accelerators of mercapto class gave medium scorch time they gave faster onset of cure than peroxide but slower than thiurams which gave the fastest onset of cure of accelerators as a whole, Viscosity of the compounds tended to increase from peroxide, sulphurless, to sulphur system. Vulcanizates with thiuram and a little sulphur showed higher tensile strength, elongation at break and lower modulus than sulphur system. The peroxide system was lower in tensile strength than both sulphur and sulphur-less system but had higher elasticity value more than other systems Thiuram cured accelerators with low sulphur gave better resistance to ageing than sulphur system. Peroxide vulcanizates gave excellent ageing characteristics. In toluene the resistance was weak for all systems however it showed the smallest ratio in peroxide system. Sulphur system showed the best resistance for processing oil (37) and peroxide system showed more resistivety than sulphur-less system
In the earliest times of America, even before Christopher Columbus sailed looking for new lands, marijuana was being used in Native American cultures for many purposes. Even now it is being used for maybe more reasons than way back when, but also as in medicinal treatments. The only difference between now and then, marijuana is used more often than none for recreational purposes.
I believe that we should we begin to manufacture one of the most destructive and powerful elements on the planet again? Nuclear chemists and engineers say yes, but the public says no. The United States stopped making this element with the United Nations ban on manufacturing nuclear weapons. But, with the continuing problem with our thinning energy resources, some want us to begin using more nuclear energy and less energy from natural resources. This paper is going to discuss what plutonium is, the advantages and disadvantages of its use, and why we should think about restarting our production of this useful element.
An atom is the basic unit of matter. It is the smallest particle of an element that retains the chemical properties of that element. The atom is indestructible and can only be seen under the most powerful microscopes. There are ninety-four natural
Penicillin was discovered by a Scottish scientist Alexander Fleming in 1928.1 However, a man named Laureate Howard Walter Florey was the first to use it as a medicine. Fleming found that certain blue-green molds inhibited the growth of the bacteria
History: No one knows how long rubber has been around. Men have discovered fossils of rubber-producing plants which appear to date back almost 3,000,000 years. Archeologists have dug up crude rubber balls in ruins
Purpose: To determine the molecular formula of CuSO4 • xH2O using the mass of percent of water.
Hypothesis: The variable x will be 5 and therefore the molecular formula will be CuSO4 • 5H2O.
Purpose / Objective: The purpose of chromatography is to separate small amounts of dissolved solids. In this experiment it used to separate the dyes in food coloring.
· Ruler to measure the 2 cm from the bottom of paper and to help draw a straight line.
The Paternò–Büchi reaction, named after two chemists who established its basic utility and form, is a photochemical reaction that forms four-membered oxetane rings from a carbonyl and an alkene. Much
Molecular Assembly and Disassembly: Photolabile Scaffolds for Molecular Recognition
The last twenty years in the chemical world have been saturated with the unrelenting quest to understand molecular recognition, especially in biological systems. Molecular recognition, although in many ways an old-fashioned term, is the most general. It describes both inter- and intramolecular interactions, and is a key