enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Valence (chemistry) - Wikipedia

    en.wikipedia.org/wiki/Valence_(chemistry)

    The valence is the combining capacity of an atom of a given element, determined by the number of hydrogen atoms that it combines with. In methane, carbon has a valence of 4; in ammonia, nitrogen has a valence of 3; in water, oxygen has a valence of 2; and in hydrogen chloride, chlorine has a valence of 1.

  3. Hume-Rothery rules - Wikipedia

    en.wikipedia.org/wiki/Hume-Rothery_rules

    [5] [6] The solute and solvent should have similar electronegativity. [7] Valency factor: two elements should have the same valence. The greater the difference in valence between solute and solvent atoms, the lower the solubility.

  4. Pauling's rules - Wikipedia

    en.wikipedia.org/wiki/Pauling's_rules

    One of Pauling's examples is olivine, M 2 SiO 4, where M is a mixture of Mg 2+ at some sites and Fe 2+ at others. The structure contains distinct SiO 4 tetrahedra which do not share any oxygens (at corners, edges or faces) with each other. The lower-valence Mg 2+ and Fe 2+ cations are surrounded by polyhedra which do share oxygens.

  5. Arsenate - Wikipedia

    en.wikipedia.org/wiki/Arsenate

    The arsenate is an ion with the chemical formula AsO 3− 4. [1] Bonding in arsenate consists of a central arsenic atom, with oxidation state +5, double bonded to one oxygen atom and single bonded to a further three oxygen atoms. [2]

  6. Reactivity series - Wikipedia

    en.wikipedia.org/wiki/Reactivity_series

    The order of reactivity, as shown by the vigour of the reaction with water or the speed at which the metal surface tarnishes in air, appears to be Cs > K > Na > Li > alkaline earth metals, i.e., alkali metals > alkaline earth metals, the same as the reverse order of the (gas-phase) ionization energies.

  7. Arsenic trisulfide - Wikipedia

    en.wikipedia.org/wiki/Arsenic_trisulfide

    Upon heating in a vacuum, polymeric As 2 S 3 "cracks" to give a mixture of molecular species, including molecular As 4 S 6. [7] [8] As 4 S 6 adopts the adamantane geometry, like that observed for P 4 O 6 and As 4 O 6. When a film of this material is exposed to an external energy source such as thermal energy (via thermal annealing [9 ...

  8. AOL Mail - AOL Help

    help.aol.com/products/aol-webmail

    Get answers to your AOL Mail, login, Desktop Gold, AOL app, password and subscription questions. Find the support options to contact customer care by email, chat, or phone number.

  9. Disproportionation - Wikipedia

    en.wikipedia.org/wiki/Disproportionation

    2 S 2 O 2− 4 + H 2 O → S 2 O 2− 3 + 2 HSO − 3. Dithionite also undergoes alkaline hydrolysis to sulfite and sulfide: [13] 3 Na 2 S 2 O 4 + 6 NaOH → 5 Na 2 SO 3 + Na 2 S + 3 H 2 O. Dithionate is prepared on a larger scale by oxidizing a cooled aqueous solution of sulfur dioxide with manganese dioxide: [14] [citation needed] 2 MnO 2 + 3 ...