The periodic table, also known as the periodic table of elements, is a tabular display of the chemical elements, which are arranged by atomic number, electron configuration, and recurring chemical properties. The structure of the table shows periodic trends. The seven rows of the table, called periods, generally have metals on the left and nonmetals on the right. The columns, called groups, contain elements with similar chemical behaviours. Six groups have accepted names as well as assigned numbers: for example, group 17 elements are the halogens; and group 18 are the noble gases. Also displayed are four simple rectangular areas or blocks associated with the filling of different atomic orbitals.
The elements from atomic numbers 1 (hydrogen) to 118 (oganesson) have all been discovered or synthesized, completing seven full rows of the periodic table. The first 94 elements, hydrogen to plutonium, all occur naturally, though some are found only in trace amounts and a few were discovered in nature only after having first been synthesized. Elements 95 to 118 have only been synthesized in laboratories, nuclear reactors, or nuclear explosions. The synthesis of elements having higher atomic numbers is currently being pursued: these elements would begin an eighth row, and theoretical work has been done to suggest possible candidates for this extension. Numerous synthetic radioisotopes of naturally occurring elements have also been produced in laboratories.
The organization of the periodic table can be used to derive relationships between the various element properties, and also to predict chemical properties and behaviours of undiscovered or newly synthesized elements. Russian chemist Dmitri Mendeleev published the first recognizable periodic table in 1869, developed mainly to illustrate periodic trends of the then-known elements. He also predicted some properties of unidentified elements that were expected to fill gaps within the table. Most of his forecasts soon proved to be correct, culminating with the discovery of gallium and germanium in 1875 and 1886 respectively, which corroborated his predictions. Mendeleev's idea has been slowly expanded and refined with the discovery or synthesis of further new elements and the development of new theoretical models to explain chemical behaviour. The modern periodic table now provides a useful framework for analyzing chemical reactions, and continues to be widely used in chemistry, nuclear physics and other sciences. Some discussion remains ongoing regarding the placement and categorisation of specific elements, the future extension and limits of the table, and whether there is an optimal form of the table.
aka "How to Rearrange the Elements Without Engaging in Alchemy"
Below is one view on what the Periodic Table might look like if it were "callibrated" in geometric fashion to the Atomic Numbers of the Earth Alkaline Metals. (red cells)
4, 20, 56 and 120 are all 4 times the sum of squares (1 + 4...
Why do metals generally have lower ionization energies than non-metals?
I mean, doesn't ionization energy depend on the atomic radius?
And the atomic radius is in turn dependent on the shell and the protons.
According to these factors, the atomic radius of Sodium should be smaller than...
How does atomic radii decrease when we move left to right in a periodic table? Though the nuclear charge increase as a result of increase in number of protons,the same increase is occurring in number of electrons.
Homework Statement
1.If protons and two neutrons are removed from the nucleus of an oxygen-16 atom, a nucleus of which element remains? electron
2. If an atom has 43 electrons, 56 neutrons and 43 protons what is its approximate atoms mass? What is the name of this element? Technetium, 99...
Greetings,
Can you match up the unearthly elements with their earthly counterpart based on the clues?
After about 9 hours of work I am stumped. Take a look at the following page:
http://www.scribd.com/doc/25315827/Alien-Periodic-Table
Please feel free to download as a word doc. I am...
How do you know how many valence energy level you have by just looking at the periodic table?
because you know that the group number tells the valence electrons right. :)
so what about valence energy level? :D
Hello everyone. I am currently studying the periodic trends in my chemistry I class. So I just want to make sure I understand the concepts.
Z effective= Atomic # - # of core electrons.
Z increases across a row and doesn't really change going down a group.
Size, radius, of atoms
the...
I am wondering if somebody can please help me to locate a very accurate, complete periodic table. Specifically, I'm looking for one that is color, contains electron configurations, and is up-to-date and accurate to the typical number of decimal places. I've searched Google and was not happy...
:frown:
Hello, guys. I need help. My professor ask us to search for the 20 scientists who prepared the Periodic Table. Well, so far, I only found 10 scientists.
1.Aristotle
2.Antoine Lavoisier
3.Jöns Jakob Berzelius
4.Johann Döbereiner
5.John Newlands
6.Lothar Meyer
7.Dmitri...
From the University of Nottingham, a video series on the 118 elements.
http://news.bbc.co.uk/1/hi/sci/tech/7507986.stm
Their website:
http://www.periodicvideos.com/
And their YouTube channel:
http://youtube.com/user/periodicvideos
Homework Statement
Element X forms a chloride, XCln which melts at 3\circC. When 0.500 g of the chloride reacts with an excess of acidified silver nitrate, 1.19g of AgCl are formed.
Another 0.500g sample of the chloride is heated strongly and chlorine gas is given off. When the residue is...
If an atom with more protons have tighter electron orbitals than atoms with fewer protons, why doesn't the "atomic radius" decrease up the periodic table? Instead it increases, why is this?
in the periodic table we have the density of each element ( density(Si) = 2.33), density(O)=1.429). i wonder how we could calculate the density of SiO2 ?
Homework Statement What information can i find on the periodic table of the elements and what does it mean
Homework Equations What is anything.
The Attempt at a Solution Atomic symbol, the big letter, for the element abervation. The elements name, for the elements name. Atomic...
Does anyone here know of a free periodic table (downloadable/printable) geared towards the needs of solid state? More specifically a table offering Lattice constants/crystallization systems, Mean Debye Temperatures etc. Ideally it would be a perfect copy of the periodic table featured by...
When I was in college years ago, I came across this test question:
How will the periodic table of elements look like in another planet?
Perhaps, it is asking for a general answer. Do you know if it will change the order of the elements?
Homework Statement
Use the periodic table to write the electron configuration of Gd.
Homework Equations
The Attempt at a Solution
Gd has 64 electrons (atomic number 64) so I would assume that the configuration would be:
1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f8 5s2 5p6 6s2...
Nowhere in my notes does it say what Eθ is and i can't find a definition of it on the internet :confused:
I'll give you the context:
For group 2 of the periodic table, state and explain the trends in the following for their elements:
(i) redox property, related to Eθ value
Are there any programs available for download that are the periodic table? I am looking for something I can keep on my laptop.
Also, can any of you recommend periodic table posters (I am looking for comprehensiveness)?
I'm designing an online periodic table of the elements and I have a question about the lanthanide and actinide families. I notice that all periodic tables put them below the main table, aligned with groups 4-18. Does this mean that they fit into those groups? Or is it just placed like that to...
Hello all. I have a quantum number question that is completely stumping me.
"In another universe, the quantum number ml = 0, 1, 2, ... + 1. That is, the values of ml are positive integers, to a maximum value of +l. All other allowed values are unchanged, so the set of allowed values is:
n...
The Janet Periodic Table of Elements (1929) seems more "consistent"
than the modern form. The location of any element (row, column) is
directly related to the quantum numbers of the most significant
electron of the element. Please see;
http://ca.geocities.com/chemguy777/index.htm
Im working on a periodic table in vb.net and I want to start adding in the information for the density, melting point and boiling point for the elements. The problem that I am having is I need to find a source that I know has only entered these values for a specific temp and pressure. I prefer...
Why are there two rows separate from the general table at the bottom of the diagram? We just started chemistry this week and I'm interested in it, I might try to get it into an online course next year if at all possible, so I just felt like asking a question.
I need to find the best oxidizing and reducing agent in the periodic table and say why i chose what i chose.
I think the best oxidizing agent is Fluorine
and the best reducing agent is Lithium I am not sure if my predictions are correct and if they are I don't know how to explain why I...
Hi guys.
I have to do a little written report about Periodic table and I have to write either about Groups, Periods or Transition elements.
I have decided to write about Periods. First I wrote what a periodic table is and how it is formed (just a little histry) then I explained the order...
Hi we're beggining to label the orbitals with s p d structures...grade 11 chemistry
The question is "Explain why the 2+ ion is the one that tends typically to form"
Ive answered the question above this one which says "Ca element 20 forms a 2+ ion. Write the electron configuration of neutral...
The only thing we know is conscious - ourselves - is a lifeform based on carbon, which is in group 4 of the Periodic Table.Silicon is too.Since silicon is found in computers this raises an intriguing possibility that computers could experience emotions and colours and sounds and so on.Silicon...
Project Help
I have a Science project due. I am a little gridlocked...
I would like to incorporate a mystery type game to this. What I have is the board and rules, but I need questions. 4 sets.
Story (For those who have completed GTA: San Andreas, you may recognize some of the scenarios)...
Periodic Table Game Project HELP!
I have a Science project due. I am a little gridlocked...
I would like to incorporate a mystery type game to this. What I have is the board and rules, but I need questions. 4 sets.
Story (For those who have completed GTA: San Andreas, you may recognize some...
I've got one of those "research in other resources" questions in my chemistry homework. (meaning the info isn't in the lecture or the text, I guess ). It goes like this:
Consider Group 1A and Group 1B of the periodic table. The text states that although A groups have very regular patterns...
I've heard that there's a periodic tables of particles, I've searched the net but have yielded little results. Is it still in the works? or is it out yet?
Hi! Does anyone know if there is a periodic table trend for the value of dipole moments...I tried looking it up on the internet and I haven't had any luck maybe someone in here knows..if you do please help! Thanks in advance!
While searching on google i came across with this very intersting periodic table where you can actually see photos of most of the elements (i hope this hasn´t been posted before).
It´s called "The Wooden Periodic Table Table" and it´s maintained by one of the founders of Wolfram Research...
Theory of everything is knowing the quantum address of all matter in our quantum tunnel. That a magnetic frequence at such a magnitude that it finds all dimensions around.
ANSWER IS =
So Fundamental Frequency is the true law of physics and anything can be created and controlled in the...
Hello all,
I was wondering if anyone could post a link to a page for a better arrangement of elements on the Periodic Table or if not, could give me an example of what a custom arrangement should look like ? Thank you in advance
Along with the nuclear atom article I have posted a unique version of the periodic table. A must see. Notice the center column of semimetals and the overall symmetry. Can be seen at [PLAIN]www.svcc.edu/~duncanb/[/URL]