G11 - CHEMISTRY (E.T)

• Element


  A pure substance that can't be broken down into simpler substances by chemical means; a substance composed of entirely one kind of atom.
• Compound


  A pure substance that can be broken down by chemical means to produce two or more pure substances; a substance containing atoms of more than one element combined in fixed proportions
• Metal


  Element that is a conductor of electricity, malleable, ductile and lustrous
• SATP


  Standard ambient temperature (25°C) and pressure (100kPA)
• STP


  Standard temperature (0°C) and pressure 101.325(kPA)
• Empirical definitions


  defines in terms of observable properties
• Non-metal


  generally a non-conductor and brittle
• Metalloid


  near "staircase line," some metallic and non metallic properties
• IUPAC


  International Union of Pure and applied chemistry. IUPAC's mission involves promoting the inter-national aspects of chemistry and applying chemistry to the service of humanity. In

  so doing, IUPAC promotes the values, standards, and ethics of science.
• Law of triads


  Johann Dobereiner's organization of elements in groups of three, in which the middle element would have properties between the other two.
• Law of Octaves


  The pattern that John Alexander Newland observed as he organized elements using increasing atomic mass.
• Empirical knowledge


  Knowledge that comes from investigation and observation.
• Theoretical knowledge


  Knowledge that explains scientific observations
• Theory


  An explanation or model based on observation, experimentation and reasoning
• Aristotle


  Creator of the four essential elements theory in which fire, water, air and Earth created matter.
• Democritus


  Argued in 400BCE that matter could be divided into small indivisible particles known as atomos (cannot be cut)
• John Dalton


  Inventor of the atomic theory in 1803
• elements, indivisible, atoms, element, identical, element, different, constant, substances, rearranged, substances, created, destroyed

  Atomic Theory fill in the blanks (Separate words with a comma and space)

  1. All______is composed of tiny ________particles known as ____

  2. All atoms of an ______ are _________

  3.Atoms of different _________s are _________

  4. Atoms of two or more elements can combine in ______ ratios to form new ___________

  5. Atoms are ________ to form new _________ in chemical

  reactions, but they are never ________ or ________
• Electron


  a negatively charged particle in an atom or ion.
• Law of conservation of mass


  States that in a chemical reaction, the mass of the products must equal the mass of the reactants.
• Law of constant composition

  Samples of a pure compound always contain the same elements in the same mass proportion.
• J.J. Thompson


  Used a cathode ray tube to discover the existence of electrons. Created the raisin bread model.
• Ernest Rutherford


  In 1909 this scientist performed a series of test in which he fired positive alpha particles through a thin sheet of gold foil. Around the foil he had a fluorescent screen which detected when the rays would deflect. Based off the percentages deflected, he hypothesized a small dense nucleus in the center of the atom.
• Proton


  a positively charged particle in the

  atom's nucleus
• Neutron


  In 1932 James Chadwick discovered this part of the atom.
• Niels Bohr


  Scientist who discovered electrons in energy levels and further created the modern atomic theory.
• Energy Level


  a theoretical sphere around an atom where electrons exist; electron orbit
• Valence shell


  the outermost energy level or orbit of an atom or ion
• Valence electron


  an electron in the outermost energy level or orbit.
• Orbit


  A spherical path in which electrons move around the nucleus
• Transition


  Movement of an electron from one enrgy level to another
• Ground state


  the lowest energy level that an electron can occupy
• line spectrum


  a pattern of distinct lines, each of which corresponds to light of a single wavelength produced when light consisting of only a few distinct wavelengths passes through a prism or spectroscope
• atomic number


  The number of protons in a specific element (A)
• mass number


  the sum of the protons and neutrons in the nucleus of an atom (Z)
• atomic mass unit


  Not the abbreviation: a very small unit that is 1/12 the mass of a carbon-12 atom
• analogy


  comparison of a situation, object or event with more familiar ones
• model


  mental or physical representation
• stable octet


  an electron arrangement where the valence shell is filled with 8 valence electrons
• Octet rule


  ageneralization stating that when atoms combine, they tend to achieve 8 valence electrons