Science:Chemistry

• Element: composed of a Nucleus, surrounded by Electrons.
• Nucleus: the center of an element atom, which is about 10,000 times bigger than the nucleus. ie. If the nucleus were the size of a golf ball, the shell, would be a km away.
  • Proton: a positively charged element, that has 1835 more mass (not the same as size) as an Electron.
  • Neutron: a neutrally charged element
• Electron: a negatively charged element, a 0.0005 times smaller than either Proton or Neutron.
• Ion: normally, the number of Electrons match the number of Protons. An ion is a Element that has more or less Electrons than Protons.
• Bond: An element can lose or gain an electron from another electron (one or both becoming ions or stopping being ions…) by bonding.
  • Ionic Bond: between between positive and negative ions.
    • Occurs between a metal and a non-metal.
    • Examples:

      • Na+ and Cl- forms NaCl
      • Mg2+ and O2- form MO
      • Mg2+ and Cl- form Mg2Cl
      • Held together by electrostatic attraction, forming a neutrally charged ionic crystal lattice. ie a Solid.
      • The number atoms in the latice are such that positive charged ions cancel the negative charged ions to be neutrally stable.
      • The crystal lattice between the elements is very strong, hence needs a lot of energy/heat to melt/break the bond between the elements. (801 degrees for Salt (NaCl), 714 degrees for Magnesium Cloride (Mg2Cl), etc.)
      • Hint: if it's a liquid or gas, it's probably not an ionic bond.
      • They do not conduct electricity when solid, but do conduct electricity when liquid, or disolved in liquid, such as water.
      • The ions break bond, and are free to move around, keeping the whole solution neutral.
      • Covalent Bond: between two non-metals.
      • They have very strong inter-atom bonding.
      • But weak inter-molecular forces. So it doesn't take much heat for molecules to melt them into solids, or boil them into gases. Hence most covalently bonded elements are liquids or gases.
      • Examples: Water:H^2O (liquid), Methane: CH^4 (gas),Ammonia:NH^3 (liquid), Carbon Dioxide: CO^2 (gas)
      • Hint: if the compound is a solid, it's probably not formed using a covalent bond.
      • They have no free electrons and no ions – so they don't conduct electricity.

      * Valence: the positive of negative 'bondability' of an element or ion. This depends on the number of electrons in the outer electron shell of element/ion.

    • Questions: So how does water conduct electricity? Because Sodium Cloride (an ionic) is soluble in water, and it does conduct electricity, when it is a liquid.
• Isotope: Normally the number of Neutrons = the number of Protons. When they do not match, it is called an Isotope of the Element.
• Shell: The number of electrons in an Element/Ion, arranged in a set of expanding concentric 'spheres'. The number of electrons that can fit on a each expanding sphere is limited by the equation 2n^2 (with variations explained later). So the first element, with one proton, therefore one electron, has one electron on its innermost sphere. The second element (He) has two protons, therefore 2 electrons on its inermost spehere. Lithing, with 3 protons, 3 electrons, can fit at most 2 on the innermost shell, then starts another shell, and uses it for the 3rd electron. Beryllium, with 4 protons, 4 electrons, has a electron configuration of 2,2.
• Happy: when an shell is filled up it called 'Happy'. ie, Helium, with 2 in the innermost shell does need any more shells, nor needs to get rid of any electrons to get back to Happy. It is considered so stable that it won't bond / marry with any other element. These types of elements, with their outer ring filled up, are called Noble elements.
• Transitive Metals: the Elements which have 2 outer electrons, but pack electrons in the second to last shell.
• Metal: Opaque, Shinny, Ductile. Conducts Heat and Electricity. Forms Basic (Base) Oxides.
• Non-Metal: Non-Conductor. Forms Acidic Oxides.
• Acidic: any Compound that form Hydrogen Ions when dissolved in water And, whose aqueous solutions react with Bases and certain metals to form Salts. Has a pH scale of <7. Turns blue litmus paper red.
• Base: Unclear.
  • https://chem.libretexts.org/Core/Physical_and_Theoretical_Chemistry/Acids_and_Bases/Acid/Overview_of_Acids_and_Bases
• Salt: TODO

  
  ## Resources ##

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