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LC Chemistry
LC Chemistry
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LC Chemistry

All Chemistry Definitions to Learn for Leaving Certificate - Higher Level

The Atom

  • Dalton’s Atomic Theory: All matter is made up of indivisible atoms which cannot be created or destroyed.
  • William Crookes discovered the Electron. Cathode ray tube.
  • JJ Thomson determined that electrons were negative. Found E/M ratio.
  • Robert Millikan’s Oil drop experiment discovered size of electron’s charge.
  • Plum Pudding Model: Solid positive sphere with electrons embedded.
  • Rutherford discovered the Nucleus. Fired alpha particles at gold foil. Proton.
  • Chadwick discovered the neutron by firing alpha particles at beryllium.
  • Energy level is the fixed energy value that an electron in an atom may have.
  • Heisenberg’s Uncertainty Principle states that it is... (More)
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LC Chemistry

Organic Chemistry – Fuels & Heats of Reaction

Organic chemistry is the chemistry of carbon containing compounds.

A hydrocarbon is a substance that contains only carbon and hydrogen.

There are three main hydrocarbons on the course – alkanes, alkenes and alkynes.

A homologous series is a series of compounds:

  • of similar chemical type.
  • that show gradual change in their physical properties.
  • all are prepared in a similar way.
  • have a common general formula
  • differ one from the next by a
  • group.

The Alkanes

The first homologous series we deal with is calles the alkanes (The ending tells us the chemical family).

Structural Isomers

Structural isomers... (More)

From looking at the past papers about 90% of the marks for Biology can be gained from knowledge of all the definitions and theory. Most questions are not direct definitions but theory questions like "describe the..." and "draw the...". Direct definitions are about 20% of the paper. As the paper is mostly theory based, calculations are quite rare unlike chemistry and physics.

For chemistry on the other hand the marks are more mixed up. I would say about 55 - 60% can be gained from definitions and theory while the rest come from calculations. The first few lab experiment and... (More)