There are currently 118 known chemical elements that show a large number of different physical and chemical properties. Among this diversity, scientists have found it useful to use names for various sets of elements, which describe similar traits, or their propensity about property. Many of these sets are officially recognized by the IUPAC standards body.
The following collective names are recommended by IUPAC:
- Alkali metals - Metals of group 1: Li, Na, K, Rb, Cs, Fr.
- Alkaline earth metals - Metals from group 2: Be, Mg, Ca, Sr, Ba, Ra.
- Pnictogen - Elements of group 15: N, P, As, Sb, Bi. (Mc has not been named when the IUPAC 2005 Red Book was published, and its chemical properties are not yet known experimentally.)
- Chalcogens - Elements of group 16: O, S, Se, Te, Po. (Lv has not been named when IUPAC 2005 Red Book was published, and its chemical properties are not yet known experimentally.)
- Halogen - Elements of group 17: F, Cl, Br, I, At. (Ts has not been named when the IUPAC 2005 Red Book was published, and its chemical properties are not yet known experimentally.)
- The noble gases - Elements of the group 18: He, Ne, Ar, Kr, Xe, Rn. (Og has not been named when the IUPAC 2005 Red Book was published, and its chemical properties are not yet known experimentally.)
- Lanthanoids - Elements 57-71: La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu.
- Actinoids - Elements 89-103: Ac, Th, Pa, U, Np, Pu, Am, Cm, Bk, Cf, Es, Fm, Md, No, Lr.
- Rare earth metals - Sc, Y, plus lanthanoids.
- Transition elements - Elements in groups of 3 to 11 or 3 to 12.
Another common classification is the level of behavior and metalloidal - metalloidal - nonmetallic characteristics. There is no general agreement on the name used for this set: in this English Wikipedia, the name used is "category". Very often this category is marked with the background color in the periodic table. The name of the category used here, without a universality claim, is:
- Alkali metals, alkaline earth metals, and noble gases: Same as the above IUPAC system.
- The transition element is called a transition metal.
- Lanthanoid and actinoid are referred to as lanthanides and actinides.
- Rare earth elements, pnictogen, chalcogens, and halogens not are used as category names, but the last three are valid as group (column) names.
- Names of additional element categories used:
- Post-transition metal - Group metals 12-17: Zn, Cd, Hg, Al, Ga, In, Tl, Sn, Pb, Bi, Po. Elements of the periods of 7 Nh, Fl, Mc, Lv, and Ts are also predicted to post-transition metals.
- Metalloids - Elements with properties between metal and non-metals: B, Si, Ge, As, Sb, Te, At.
- Non-metals reactive - Non-metals which are chemically active (as opposed to noble gases): H, C, N, P, O, S, Se, F, Cl, Br, I
- Superactinides - A series of hypotheses from elements 121 to 157, which includes the predicted "g-block" of the periodic table.
Many other names for the commonly used element set, but others have been used throughout history. This set usually does not aim to cover the entire periodic table (such as no period ). Some examples:
- Precious metals - Diverse metals of highly radioactive, high-value metals.
- Coin metals - Various metals used for mint coins, especially the group elements 11 Cu, Ag, and Au.
- Platinum Group - Ru, Rh, Pd, Os, Ir, Pt.
- Precious metals - A broadly defined group of metals that are resistant to corrosion. Usually includes Ag, Au, and platinum group metals.
- Heavy metals - Various groups of undefined metals, based on density, atomic number, or toxicity.
- Original Metal - Metal that occurs purely in nature, including precious and other metals such as Sn and Pb.
- Earth Metals - An old historical term, usually called group metals 3 and 13, although sometimes others such as beryllium and chromium are also included.
- Transuranium element - Element with atomic number greater than 92.
- Elements of transactinide - Elements after actinide (atomic number greater than 103).
- Elements of transplutonium - Elements with atomic numbers greater than 94.
- Minor actinides - Actinides are found in significant quantities in nuclear fuel, other than U and Pu: Np, Am, Cm.
- The heavy atom - a term used in computational chemistry to refer to any element other than hydrogen and helium.
Video Names for sets of chemical elements
References
Source of the article : Wikipedia
0 Comments