- Count Lev Nikolayevich Tolstoy (/ˈtoʊlstɔɪ, ˈtɒl-/; Russian: Лев Николаевич Толстой, IPA: [ˈlʲef nʲɪkɐˈla(j)ɪvʲɪtɕ tɐlˈstoj]; 9 September [O.S. 28 August] 1828 – 20 November [O.S. 7 November] 1910), usually referred to in English as Leo Tolstoy, was a Russian writer who is regarded as one of the greatest authors of all time. He received nominations for the Nobel Prize in Literature every year from 1902 to 1906 and for the Nobel Peace Prize in 1901, 1902, and 1909; the fact that he never won is a major controversy.
- Calcium (Wikipedia)
Calcium is a chemical element; it has symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar to its heavier homologues strontium and barium. It is the fifth most abundant element in Earth’s crust, and the third most abundant metal, after iron and aluminium. The most common calcium compound on Earth is calcium carbonate, found in limestone and the fossilised remnants of early sea life; gypsum, anhydrite, fluorite, and apatite are also sources of calcium. The name derives from Latin calx “lime”, which was obtained from heating limestone.