Electron Configuration This is the first element to be discovered by a bankrupt German merchant in while he was searching for the "philospher's stone" Phosphorus What is the distance from the center of an atom's nucleus to its outer most electron? Atomic Radius What is the name of element number and what is the atomic number?
But its design continues to evolve and is the source of much debate The periodic table has been around for almost years and has survived many revolutionary discoveries including that of subatomic structure and the development of quantum mechanics and relativity.
The order of the elements was originally provided by their increasing atomic weights figure 1 but it was later found that atomic number provided a better ordering principle.
For example, the elements tellurium and iodine fell perfectly into place according to their chemical behaviour but their position in the table would have been inverted if ordered strictly by their atomic weights.
Order for the elements Source: But Elements of periodic table trivia periodic table is a two-dimensional representation obtained by 'snipping' the one-dimensional sequence at certain points and placing the following sequences of elements underneath the previous strips or sequences.
Where ordering based on atomic number can be thought of as a primary classification, the vertical grouping of elements that are obtained by the snipping and placing procedure may be thought of providing a secondary classification. Quantum mechanical solution The modern explanation why the elements fall into vertical columns, showing similar properties, has been provided by quantum mechanics and describes the shell structure of electrons orbiting the nucleus of each kind of atom.
The elements in group 1, for example, all have one outer-shell electron although they differ in their inner shell structures.
Lithium 1s2 2s1 Sodium 1s2 2s2 2p6 3s1 Potassium 1s2 2s2 2p6 3s2 3p6 4s1 It is the outer-shell electrons which govern their chemical properties and that's why they behave similarly.
For instance, all these metals react with water, although the reactivity increases as one descends the group from lithium to potassium and beyond to caesium and rubidium. An abundance of designs Given these basic facts it is a little surprising to find so many different forms of the periodic table.
In the conventional modern periodic table, known as the medium-long form, these elements fall into groups 1 and 18 respectively - the alkali metals and the noble gases figure 2.
The initial unevenness occurs because the alkali and alkaline earth metals fall on the left as a tall block followed by a shallower ten element-wide block containing the transition metals. This is followed on the right edge by another taller block, which is six elements wide and contains a mixture of metals, semi-metals and non-metals.
In quantum mechanical terms these blocks are characterised by the filling of from left to right s orbitals, d orbitals and p orbitals. There is a further oddity in the disconnected block of elements that appears as a kind of footnote to the entire system. These elements involve the filling of f orbitals.
A place for helium Another more regular representation, the left-step table figure 3was proposed almost 90 years ago by the Frenchman, Charles Janet. Figure 3 - A left step periodic table Recently this form has enjoyed a revival because it also seems to display the order of orbital filling more clearly than the conventional form.
There is an annoying drawback in that the element helium is removed from its usual place among the noble gases and moved to join the alkaline earths like beryllium, magnesium and calcium.
This move can be justified on the basis of the outer-electron structure of helium, which possesses two such electrons, as do the members of the alkaline earth group. From a chemical point of view, the placement of helium among these metals amounts to complete heresy.
This question of where to place helium is one sign of trouble in the periodic table. Hydrogen doesn't fit either Even the first element, hydrogen, has been causing trouble for some time.Learn the elements of the periodic table by clicking on them.
Play! Play! Level 1 - Element Matching Game: Level 1 - Beginner: Click on the correct element group that coresponds to the clue about it. click on the correct chemical symbol for the named element. Play! Common Elements.
. Quiz # PRACTICE: Periodic Table, Groups & Trends. Quiz # PRACTICE: Periodic Table, Groups & Trends For each of the following questions or statements, select the most appropriate response and click its letter: Start. Congratulations - you have completed Quiz # PRACTICE: Periodic Table. The periodic table we use today is based on the one devised and published by Dmitri Mendeleev in Mendeleev found he could arrange the 65 elements then known in a grid or table so that each element .
Periodic Table Of Elements. SUBMITTED BY: FRANCINE LALAINE DE OCAMPO SUBMITTED TO: PROF. MARIBEL CRUZ the periodic table can help predict the properties of various elements and the relations between properties.
it provides a useful framework for analyzing chemical behavior. electron configurations. and is widely used in chemistry and other sciences. Chemistry > Element Quiz This is a chemistry game that teaches facts about the elements, their symbols, and their uses.
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