Madeleev originally arranged the elements in the first periodic table by their average atomic masses. Later it was changed to atomic number by Moseley, or the number of protons each of that element's atom has.
mendeleve arranged the elements in order of increasing atomic mass. He also placed elements with the same chemical properties in the same columns.
Mendeleev arranged the elements known at the time in the order of their relative Atomic Mass .!
The principle is: periodical change of the chemical or physical properties of elements.
This was the periodicity of chemical properties of elements.
atomic mass.
ascending order of mass
Mendeleev ordered the elements from lowest atomic mass unit (amu) to highest atomic mass unit.
The physical property that can render tungsten suitable for making filament of tungsten light bulbs is incandescence.
that reason is because when you mix some chemicals and colors you can get the property of paint or if you mess up the chemicals you could end up with something that is totally different that could be dangrous like a gas that can kill you which is bad for your health.
Atomic number and electron configurationElements in the periodic table are arranged in order of increasing atomic number (which is just the number of protons found in the nucleus of that element). Starting with hydrogen (H) with only 1 proton and reading left to right and then down, the atomic number goes up one for each element until you reach the highest atomic number of 106. The reason the periodic table is the shape that it is has to do with the electronic configurations of the elements. The periodic table is arranged so that all the elements in each period (row) have similar electronic configurations to the other elements in that period. That also often means that elements in the same group (column) show similar chemical reactivity. Electrons in atoms are arranged in different orbitals (named "s", "p", "d", "f"). Elements in the same group all have the same number of electrons in their outer orbitals.For instance, the alkali metals in the first column (lithium, sodium, potassium, rubidium, cesium, and francium) all have 1 electron in their outermost shell/layer (it turns out there are many shell, each one bigger than the previous one -- lithium has 2 shells while bigger atoms like cesium have 6 shells). What matters is that they all have a single electron in that outermost shell, regardless of how many shells they have in total. This same trend is observed in each group of the table, excluding most of the transition metals.I've linked my source for this answer below.
In the alkali metals and the alkaline earth metals (groups IA and IIA on the periodic table), all increase in reactivity as one goes down the columns. These elements react by loaning out electrons, and it is easier to loan out an electron if the valence band where that lone electron (group IA) or two (group IIA) hangs out is farther from the nucleus and is screened by other (more) electrons in lower bands. The elements farther down the columns are more reactive because they can more easily loan out electrons. Just as an aside, one might expect that the elements that borrow electrons might be better able to do that if there was less electron screening, right? And that would suggest that the elements higher in the columns of the groups that are seriously interested in borrowing electrons (think group VIIA) would be more reactive than the lower ones, wouldn't it? Maybe that's why fluorine is called the hungry wolf of the periodic table.
After atomic numbers Henry Moseley supported the arrangement of periodic table of Mendeleev after atomic numbers and properties by a strong physical conception: study of the lines of X-ray spectra of chemical elements. It is a true relation between atomic numbers of elements and the wavelenghts of the characteristic X-ray lines.
Scientists suggest Mendeleev left gaps in the periodic table because Mendeleev knew the elements existed; however, was unable to prove it.
Mendeleev noticed that when elements are arranged in order of increasing atomic mass, their properties repeat periodically. He observed that elements with similar properties fall into vertical columns, or groups, and that there are empty spaces within the periodic table that suggest the existence of yet-to-be-discovered elements. He also noticed that the atomic mass of an element is not always the best indicator of its properties, and sometimes elements with similar properties have different atomic masses.
I suggest the property is inequality.
DNA molecules are arranged as a tightly coiled helix. (:
Massive, I suggest you try to stop it
Notion in compositional theory that objects arranged on a S-shaped line suggest grace and beauty.
I suggest you go see your gyno to find out why it is irregular. First then can they help you.
I suggest making flashcards if you are a visual learner. If you are an auditory learner (hearing) than i suggest repeating them out loud or listening to them. If you are an kinetic learner (doing) than i suggest that you make up some sort of game for them.
There are so many companies who sells the property insurance but i would suggest you www.USAA.com or www.NetQuote.com/Homeowner
For Fifa 11 I suggest the PS3 for the controllers are better arranged for the gaming experience, but if you'd like to play online, I suggest the Xbox for the servers have less lag (more dedicated servers).
Mendeleev ordered the elements from lowest atomic mass unit (amu) to highest atomic mass unit.