When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. List of chemical elements - Wikipedia

    en.wikipedia.org/wiki/List_of_chemical_elements

    118 chemical elements have been identified and named officially by IUPAC.A chemical element, often simply called an element, is a type of atom which has a specific number of protons in its atomic nucleus (i.e., a specific atomic number, or Z).

  3. Template:Periodic table (group names) - Wikipedia

    en.wikipedia.org/wiki/Template:Periodic_table...

    Elements of the group have one s-electron in the outer electron shell. Hydrogen is not considered to be an alkali metal as it is not a metal, though it is more analogous to them than any other group. This makes the group somewhat exceptional. b The 14 f-block groups (columns) do not have a group number.

  4. Lewis structure - Wikipedia

    en.wikipedia.org/wiki/Lewis_structure

    Count valence electrons. Nitrogen has 5 valence electrons; each oxygen has 6, for a total of (6 × 2) + 5 = 17. The ion has a charge of −1, which indicates an extra electron, so the total number of electrons is 18. Connect the atoms by single bonds. Each oxygen must be bonded to the nitrogen, which uses four electrons—two in each bond.

  5. Periodic table - Wikipedia

    en.wikipedia.org/wiki/Periodic_table

    Boron (1s 2 2s 2 2p 1) puts its new electron in a 2p orbital; carbon (1s 2 2s 2 2p 2) fills a second 2p orbital; and with nitrogen (1s 2 2s 2 2p 3) all three 2p orbitals become singly occupied. This is consistent with Hund's rule , which states that atoms usually prefer to singly occupy each orbital of the same type before filling them with the ...

  6. Periodic table (electron configurations) - Wikipedia

    en.wikipedia.org/wiki/Periodic_table_(electron...

    Og, 118, oganesson : 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 6 5s 2 4d 10 5p 6 6s 2 4f 14 5d 10 6p 6 7s 2 5f 14 6d 10 7p 6 Note that these electron configurations are given for neutral atoms in the gas phase, which are not the same as the electron configurations for the same atoms in chemical environments.

  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. Tin - Wikipedia

    en.wikipedia.org/wiki/Tin

    Tin is a post-transition metal in group 14 of the periodic table of elements. It is obtained chiefly from the mineral cassiterite, which contains stannic oxide, SnO 2. 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

  9. Sulfide - Wikipedia

    en.wikipedia.org/wiki/Sulfide

    The sulfide ion does not exist in aqueous alkaline solutions of Na 2 S. [3] [4] Instead sulfide converts to hydrosulfide: S 2− + H 2 O → SH − + OH −. Upon treatment with an acid, sulfide salts convert to hydrogen sulfide: S 2− + H + → SH − SH − + H + → H 2 S. Oxidation of sulfide is a complicated process.