When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. Transition metal - Wikipedia

    en.wikipedia.org/wiki/Transition_metal

    The first transition series is present in the 4th period, and starts after Ca (Z = 20) of group 2 with the configuration [Ar]4s 2, or scandium (Sc), the first element of group 3 with atomic number Z = 21 and configuration [Ar]4s 2 3d 1, depending on the definition used. As we move from left to right, electrons are added to the same d subshell ...

  3. Iron - Wikipedia

    en.wikipedia.org/wiki/Iron

    It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, forming much of Earth's outer and inner core. It is the fourth most abundant element in the Earth's crust, being mainly deposited by meteorites in its metallic state.

  4. 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.

  5. History of the periodic table - Wikipedia

    en.wikipedia.org/wiki/History_of_the_periodic_table

    This is an accepted version of this page This is the latest accepted revision, reviewed on 28 January 2025. Development of the table of chemical elements The American chemist Glenn T. Seaborg —after whom the element seaborgium is named—standing in front of a periodic table, May 19, 1950 Part of a series on the Periodic table Periodic table forms 18-column 32-column Alternative and extended ...

  6. Periodic table - Wikipedia

    en.wikipedia.org/wiki/Periodic_table

    The first periodic table to become generally accepted was ... thereafter, a series of ten transition elements ... the first element to be discovered by synthesis ...

  7. Period (periodic table) - Wikipedia

    en.wikipedia.org/wiki/Period_(periodic_table)

    Period 4 includes the biologically essential elements potassium and calcium, and is the first period in the d-block with the lighter transition metals. These include iron, the heaviest element forged in main-sequence stars and a principal component of the Earth, as well as other important metals such as cobalt, nickel, and copper. Almost all ...

  8. Electron configuration - Wikipedia

    en.wikipedia.org/wiki/Electron_configuration

    After calcium, most neutral atoms in the first series of transition metals (scandium through zinc) have configurations with two 4s electrons, but there are two exceptions. Chromium and copper have electron configurations [Ar] 3d 5 4s 1 and [Ar] 3d 10 4s 1 respectively, i.e. one electron has passed from the 4s-orbital to a 3d-orbital to generate ...

  9. Reactivity series - Wikipedia

    en.wikipedia.org/wiki/Reactivity_series

    electronegative metals with values between 1.9 and 2.54. From the image, the group 1–2 metals and the lanthanides and actinides are very electropositive to electropositive; the transition metals in groups 3 to 12 are very electropositive to electronegative; and the post-transition metals are electropositive