Search results
Results from the WOW.Com Content Network
In chemistry, periodic trends are specific patterns present in the periodic table that illustrate different aspects of certain elements when grouped by period and/or group. They were discovered by the Russian chemist Dmitri Mendeleev in 1863.
In chemistry, a reactivity series (or reactivity series of elements) is an empirical, calculated, and structurally analytical progression [1] of a series of metals, arranged by their "reactivity" from highest to lowest. [2] [3] [4] It is used to summarize information about the reactions of metals with acids and water, single displacement ...
The alkaline earth metals are six chemical elements in group 2 of the periodic table. They are beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra). [ 1 ] The elements have very similar properties: they are all shiny, silvery-white, somewhat reactive metals at standard temperature and pressure .
Group 2: Alkaline earth metals. The alkaline earth metals (Be, Mg, Ca, Sr, Ba, and Ra) are the second most reactive metals in the periodic table, and, like the Group 1 metals, have increasing reactivity with increasing numbers of energy levels.
Due to the basicity of the Se 2− and Te 2− ions, the alkali metal selenides and tellurides are alkaline in solution; when reacted directly with selenium and tellurium, alkali metal polyselenides and polytellurides are formed along with the selenides and tellurides with the Se 2− x and Te 2− x ions. [132]
For alkali metal cation trend, when triphenylphosphine group is present, changing from M = Li to M = K favored in phosphine group leaving by 9%. Although it is a small effect compared to leaving group effect, this is due to Lewis acidity [ 8 ] on metal cations because a stronger Lewis acidic metal cation (Li > K in Lewis acidity) attracts tosyl ...
Nevertheless, one can generally examine acid dissociation constants to qualitatively predict or rationalize rate or reactivity trends relating to variation of the leaving group. Consistent with this picture, strong bases such as OH − , OR 2 and NR − 2 tend to make poor leaving groups, due their inability to stabilize a negative charge.
A period 2 element is one of the chemical elements in the second row (or period) of the periodic table of the chemical elements.The periodic table is laid out in rows to illustrate recurring (periodic) trends in the chemical behavior of the elements as their atomic number increases; a new row is started when chemical behavior begins to repeat, creating columns of elements with similar properties.