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The heavier alkaline earth metals react more vigorously than the lighter ones. [2] The alkaline earth metals have the second-lowest first ionization energies in their respective periods of the periodic table [4] because of their somewhat low effective nuclear charges and the ability to attain a full outer shell configuration by losing just two ...
Radium is the heaviest known alkaline earth metal and is the only radioactive member of its group. Its physical and chemical properties most closely resemble its lighter congener, barium. [4] Pure radium is a volatile, lustrous silvery-white metal, even though its lighter congeners calcium, strontium, and barium have a slight yellow tint. [4]
This is an accepted version of this page This is the latest accepted revision, reviewed on 9 January 2025. Hypothetical chemical element, symbol Uue and atomic number 119 Chemical element with atomic number 119 (Uue) Ununennium, 119 Uue Theoretical element Ununennium Pronunciation / ˌ uː n. uː n ˈ ɛ n i ə m / ⓘ (OON -oon- EN -ee-əm) Alternative names element 119, eka-francium ...
Barium found in the Earth's crust is a mixture of seven primordial nuclides, barium-130, 132, and 134 through 138. [15] Barium-130 undergoes very slow radioactive decay to xenon -130 by double beta plus decay , with a half-life of (0.5–2.7)×10 21 years (about 10 11 times the age of the universe).
Rubidium is the first alkali metal in the group to have a density higher than water. On Earth, natural rubidium comprises two isotopes: 72% is a stable isotope 85 Rb, and 28% is slightly radioactive 87 Rb, with a half-life of 48.8 billion years – more than three times as long as the estimated age of the universe.
The alkaline earth metal strontium (38 Sr) has four stable, naturally occurring isotopes: 84 Sr (0.56%), 86 Sr (9.86%), 87 Sr (7.0%) and 88 Sr (82.58%). Its standard atomic weight is 87.62(1). Only 87 Sr is radiogenic ; it is produced by decay from the radioactive alkali metal 87 Rb , which has a half-life of 4.88 × 10 10 years (i.e. more than ...
All period three elements occur in nature and have at least one stable isotope. All but the noble gas argon are essential to basic geology and biology. Sodium (Na) is an alkali metal. It is present in Earth's oceans in large quantities in the form of sodium chloride (table salt). Magnesium (Mg) is an alkaline earth metal.
An alkaline earth metal, strontium is a soft silver-white yellowish metallic element that is highly chemically reactive. The metal forms a dark oxide layer when it is exposed to air. Strontium has physical and chemical properties similar to those of its two vertical neighbors in the periodic table, calcium and barium.