Elements and compounds are both pure substances because they cannot be split apart by physical or mechanical methods. Some examples of elements are nickel, carbon and oxygen, while some examples of compounds are water and sodium chloride.
An element is any base atom that is from the periodic table of elements. A compound, however, can be any molecule that is made from two or more atoms of the same or different elements. Water is made of two hydrogen atoms and one oxygen atom. It is a pure substance because it has a single base molecule of H2O. A mixture is not a pure substance because it is made of two or more compounds that could be separated.Learn More
The most common chemical formulas for chalk are CaCO3 (calcium carbonate) and CaO (calcium oxide). Chalk is a soft, porous sedimentary rock that is a form of limestone and is mainly composed of calcite (calcium carbonate).Full Answer >
Solid iodine consists of shiny bluish-black crystals, but iodine vapors are a purple gas. Iodine is named after the appearance of the iodine vapors, as "iodes" is the Greek word for purple.Full Answer >
Every atom is made up of a nucleus surrounded by electrons that orbit the nucleus. Electrons orbit the nucleus because they are attracted to the protons inside of the nucleus while simultaneously repelled by the other electrons.Full Answer >
Nitrogen triiodide is an extremely powerful contact explosive with the formula NI3. Small quantities of dry nitrogen triiodide explode with a loud snap and are set off by a light touch or vibration. Nitrogen triiodide is created through the reaction of iodine with ammonia.Full Answer >