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Nickel titanium, also known as nitinol, is a metal alloy of nickel and titanium, where the two elements are present in roughly equal atomic percentages.Different alloys are named according to the weight percentage of nickel; e.g., nitinol 55 and nitinol 60.
Periodic table of the chemical elements showing the most or more commonly named sets of elements (in periodic tables), and a traditional dividing line between metals and nonmetals. The f-block actually fits between groups 2 and 3 ; it is usually shown at the foot of the table to save horizontal space.
In the periodic table of the elements, each column is a group. In chemistry, a group (also known as a family) [1] is a column of elements in the periodic table of the chemical elements. There are 18 numbered groups in the periodic table; the 14 f-block columns, between groups 2 and 3, are not numbered.
Like the periodic table, the list below organizes the elements by the number of protons in their atoms; it can also be organized by other properties, such as atomic weight, density, and electronegativity. For more detailed information about the origins of element names, see List of chemical element name etymologies.
The 2011 IUPAC Principles of Chemical Nomenclature describe a "transition metal" as any element in groups 3 to 12 on the periodic table. [4] This corresponds exactly to the d-block elements, and many scientists use this definition. [5] [6] In actual practice, the f-block lanthanide and actinide series are called "inner transition metals".
[33] 48 Ni, discovered in 1999, is the most proton-rich heavy element isotope known. With 28 protons and 20 neutrons, 48 Ni is "doubly magic", as is 78 Ni with 28 protons and 50 neutrons. Both are therefore unusually stable for nuclei with so large a proton–neutron imbalance. [9] [34]
Naturally occurring titanium is composed of five stable isotopes: 46 Ti, 47 Ti, 48 Ti, 49 Ti, and 50 Ti, with 48 Ti being the most abundant (73.8% natural abundance). At least 21 radioisotopes have been characterized, the most stable of which are 44 Ti with a half-life of 63 years; 45 Ti, 184.8 minutes; 51 Ti, 5.76 minutes; and 52 Ti, 1.7 minutes
The image shows a periodic table extract with the electronegativity values of metals. [12] Wulfsberg [13] distinguishes: very electropositive metals with electronegativity values below 1.4 electropositive metals with values between 1.4 and 1.9; and electronegative metals with values between 1.9 and 2.54.