See also the "Related Questions" link to the left of this answer: "Why are elements arranged as they are in the Periodic Table?" Once you've looked at the question above, read this: The gaps are due to the fact that the different electron orbitals (s, p, d, f) hold different numbers of electrons each. An s-orbital can hold at most 2 electrons, while a p-orbital can hold up to 6, a d-orbital can hold up to 10, and an f-orbital can hold as many as 14 electrons. In order to align the columns of the periodic table so that each element in the column has the same outermost (or valence) electron configuration, there need to be gaps. Actually, if you look at the modern periodic table, there is always a block of elements separate from the others (called the Lanthanides and Actinides, or the f-block elements) at the bottom. You can actually draw the periodic table with even bigger gaps is if you include those together with the rest of the elements. Drawing it this way is cumbersome because it is so long and narrow, but it is actually a better way to see the trends in the electron configurations. See the Web Links to the left for periodic tables that show the electron configurations of each element, as well as this funny looking stretched out version with the f-block elements all in the same table.
mendeleevs left the gaps for the elements that's hadnt been dicovered by then but he pridicted that more element can be discovered in the future and placed them according to their properties after a specific period.Some elements pridicted by mendeleevs were eka aluminum which we today call galium.Eka means an element with similar properties to that of aluminum and galium does have properties similar to aluminum.
You will not really find "holes" in modern periodic tables of the elements. However, to explain why older tables did indeed have holes requires a little bit of history:
When scientists first began really probing the secrets of the atom, and began to understand how they were formed and under what natural laws, certain patterns emerged. These patterns included things like the weight of the nucleus, the number of electrons and so on.
The periodic table was then filled in according to those laws and elements were filled in. However, there were many cases where we thought there should be an element present, but we had not yet discovered it (or, as in the case of some of the latest additions to the table, we actually had to create these elements in a laboratory). As more information came in, scientists realized that there initial ideas were indeed correct and the holes have since been filled in.
There is a section cut out of the Periodic Table of Chemical Elements just for the fact that all of it wouldn't fit, so it got put down under but should still be pictured as being part of groups 6 and 7
for future additions hat will be discovered
they are artificially made elements added to the periodic table
because those elements were not discovered at that time
Because the element with atomic number is not yet discovered.
The holes or gaps represented undiscovered elements. These were discovered later.
He observed that the elements properties do not fit on a column in some cases and assumed that a new element must be interleaved, not yet discovered in his time.
No, there are not.
You shove the peridic table up your a hole
No. The elements in group 1 (the alkali metals) are very soft, easily cut with a knife, and are highly reactive and react violently with water and oxygen. They are anything but strong, hard and corrosion-resistant.
The elements at the far left of the periodic table are called the "alkali metals," which are soft enough to be cut with a knife and reactive enough you'll never find them in nature as pure elements, only as salts.
If you mean the elements in the Periodic Table it is carbon. If your talking about in general, diamond is by far the strongest element known to human.
Any of the alkali metals (in group one of the periodic table)
You shove the peridic table up your a hole
No. The elements in group 1 (the alkali metals) are very soft, easily cut with a knife, and are highly reactive and react violently with water and oxygen. They are anything but strong, hard and corrosion-resistant.
The elements at the far left of the periodic table are called the "alkali metals," which are soft enough to be cut with a knife and reactive enough you'll never find them in nature as pure elements, only as salts.
In one of the cut-scenes of Black Ops there is an image of the periodic table of elements. on it here are two elements that are circled (Re &Nd). This may have something to do with it.
The simple answer :Praeseodymium is a metal.DetailsIt can be found in the lanthanoids section of a periodic tableIt is very soft, and can be easily cut simply with a knife.As it is in the lanthanoids group in the periodic table you can tell it's outer electron is on the f-electron shell.melting point: 1204Kboiling point: 3563K
If you mean the elements in the Periodic Table it is carbon. If your talking about in general, diamond is by far the strongest element known to human.
Lithium is a metal, it looks silvery and is shiney when freshly cut but will tarnish quickly in air. It is the lightest metal and is normally stored under oil in airtight jars as its very reactive with water.
Potassium is an alkali metal.It is shiny when freshly cut but quickly go dull.
Any of the alkali metals (in group one of the periodic table)
Between the girdle and the table (top) are facets.
The elements proceed in order of increasing atomic number as you read left to right, line by line downwards. The lines (periods) are cut off at the point where a full valence shall is reached; the gaps in the upper/earlier periods is used to match the orbitals being filled in successive periods.
Brilliant cut assumes a round shape. The elements of this cut are table, girdle, crown, pavilion and diameter. As well, the shapes of the facets have names: star, upper girdle and kite.