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  2. Tin - Wikipedia

    en.wikipedia.org/wiki/Tin

    Tin shows a chemical similarity to both of its neighbors in group 14, germanium and lead, and has two main oxidation states, +2 and the slightly more stable +4. Tin is the 49th most abundant element on Earth, making up 0.00022% of its crust, and with 10 stable isotopes, it has the largest number of stable isotopes in the periodic table, due to ...

  3. Nucleophilic substitution - Wikipedia

    en.wikipedia.org/wiki/Nucleophilic_substitution

    In chemistry, a nucleophilic substitution (S N) is a class of chemical reactions in which an electron-rich chemical species (known as a nucleophile) replaces a functional group within another electron-deficient molecule (known as the electrophile). The molecule that contains the electrophile and the leaving functional group is called the substrate.

  4. Chemical symbol - Wikipedia

    en.wikipedia.org/wiki/Chemical_symbol

    Chemical symbols are the abbreviations used in chemistry, mainly for chemical elements; but also for functional groups, chemical compounds, and other entities. Element symbols for chemical elements, also known as atomic symbols , normally consist of one or two letters from the Latin alphabet and are written with the first letter capitalised.

  5. Names for sets of chemical elements - Wikipedia

    en.wikipedia.org/wiki/Names_for_sets_of_chemical...

    Heavy atom – term used in computational chemistry to refer to any element other than hydrogen and helium. Minor actinides – Actinides found in significant quantities in nuclear fuel, other than U and Pu: Np, Am, Cm. Native metals – Metals that occur pure in nature, including the noble metals and others such as Sn and Pb.

  6. SN1 reaction - Wikipedia

    en.wikipedia.org/wiki/SN1_reaction

    The unimolecular nucleophilic substitution (S N 1) reaction is a substitution reaction in organic chemistry. The Hughes-Ingold symbol of the mechanism expresses two properties—"S N" stands for "nucleophilic substitution", and the "1" says that the rate-determining step is unimolecular.

  7. List of chemistry mnemonics - Wikipedia

    en.wikipedia.org/wiki/List_of_chemistry_mnemonics

    A mnemonic is a memory aid used to improve long-term memory and make the process of consolidation easier. Many chemistry aspects, rules, names of compounds, sequences of elements, their reactivity, etc., can be easily and efficiently memorized with the help of mnemonics.

  8. Periodic table - Wikipedia

    en.wikipedia.org/wiki/Periodic_table

    Each chemical element has a unique atomic number (Z— for "Zahl", German for "number") representing the number of protons in its nucleus. [4] Each distinct atomic number therefore corresponds to a class of atom: these classes are called the chemical elements. [5] The chemical elements are what the periodic table classifies and organizes.

  9. SN2 reaction - Wikipedia

    en.wikipedia.org/wiki/SN2_reaction

    The bimolecular nucleophilic substitution (S N 2) is a type of reaction mechanism that is common in organic chemistry. In the S N 2 reaction, a strong nucleophile forms a new bond to an sp 3-hybridised carbon atom via a backside attack, all while the leaving group detaches from the reaction center in a concerted (i.e. simultaneous) fashion.