Search results
Results From The WOW.Com Content Network
The periodic table, also known as the periodic table of the elements, is an ordered arrangement of the chemical elements into rows ("periods") and columns ("groups"). It is an icon of chemistry and is widely used in physics and other sciences.
These elements originally referred to earth, water, air and fire rather than the chemical elements of modern science. The term 'elements' ( stoicheia ) was first used by Greek philosopher Plato around 360 BCE in his dialogue Timaeus , which includes a discussion of the composition of inorganic and organic bodies and is a speculative treatise on ...
Promethium is not an easy image to find, however, out of all the elements without a picture, it is one of the two most likely to have a picture discovered. The only pictures floating around the place are of promethium chloride and promethium oxide, but not the metal itself. This is likely because the metal is not used for anything, it's hard to ...
A chemical element, often simply called an element, is a type of atom which has a specific number of protons in its atomic nucleus (i.e., a specific atomic number, or Z). [ 1 ] The definitive visualisation of all 118 elements is the periodic table of the elements , whose history along the principles of the periodic law was one of the founding ...
The basest element, earth, created using all the other elements, can be perceived by all five senses — (i) hearing, (ii) touch, (iii) sight, (iv) taste, and (v) smell. The next higher element, water, has no odor but can be heard, felt, seen and tasted. Next comes fire, which can be heard, felt and seen. Air can be heard and felt.
In the periodic table of the elements, each numbered row is a period. A period on the periodic table is a row of chemical elements. All elements in a row have the same number of electron shells. Each next element in a period has one more proton and is less metallic than its predecessor.
Many elements display multiple valences, or tendencies to share differing numbers of electrons in different compounds. Thus, chemical bonding between these elements takes many forms of electron-sharing that are more than simple electron transfers. Examples include the element carbon and the organic compounds. [98]
For some elements, this is because the material was known in ancient times, while for others, the name is a more recent invention. For example, Pb is the symbol for lead (plumbum in Latin); Hg is the symbol for mercury (hydrargyrum in Greek); and He is the symbol for helium (a Neo-Latin name) because helium was not known in ancient Roman times.