By: Shaheen Daad
In a mixture there are two or more substances combined which have not reacted chemically with each other. In other words, nothing further than mixing has taken place. Each constituent remain intact within it, and are able to demonstrate all the chemical properties that characterize...
By: Shaheen Daad
According to the ancient Greek philosopher Heraclitus, one cannot step into the same river twice. This expresses the fact that everything in the world is subject to change. Yet the Mississippi River may still be called the Mississippi River, so they must be something there...
By: Santi Meintjes
Iodine was discovered by accident in 1811 by the French chemist Bernard Courtois. It is one of the better known elements among the general public, due to the very valuable property that it kills germs, mainly bacteria. Iodine (also known as Lugol after the physician...
By: Shaheen Daad
Still waters are said to run deep. It is clear that something is causing it to stay still, since the more "normal" waters surrounding it are swaying and heaving in every manner. It may also be appreciated that the cause is not a trivial one...
By: Shaheen Daad
A gaseous substance will be called a gas if it is above its boiling point, but a vapor if it is below. This sounds precise enough, but actually it is not. There is a lot of confusion to be sorted out. If you leave a...
By: Michael Totten
Astronomy is the study of celestial objects, which are objects in the sky, as opposed to terrestrial objects, which are found on Earth. Modern astronomy begins where Earth's atmosphere ends.The Earth-Moon systemEarth has a single moon, the Moon. The Earth and Moon orbit each...
By: Shannon Farlouis
Lead is a dense metallic element that is extracted from the earth. This element has many common uses like plumbing, batteries, radiation shielding and solder. Lead is soft and is bluish-white in color. Lead is also added to paints and is used to make certain...
By: Retha Boswell
Bismuth (atomic symbol Bi) is in group 15 and period 6 of the periodic table and is classified as one of the “other metals” along with aluminum, gallium, indium, tin, thallium and lead. Bismuth was actually believed to be a form of lead or...
By: Michael Totten
The human eye is extremely sensitive to the sun's light. Even a glance at the sun will cause after-images, as a result of overexposure to strong light. Looking at the sun directly, even for a few seconds, can cause permanent burns to the retina at...
By: Retha Boswell
Hydrogen (atomic symbol H) is the first element on the periodic table and the lightest of all the elements. It is composed of a single electron and a single proton. By weight it makes up 90 percent of the universe. This is because it is...

 

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