Flashcards
definitions
Flashcards do conjunto (12)
- 1An elementA substance that can't be broken down into a simpler form by chemical means.
- 2Dobreiners triadsElements arranged in groups of three where they all have similar characteristics and the sum of the middle element is the average of the sum of the other two elements
- 3Newmans octaveselements arranged according to increasing atomic weight where the mass of the first and eight elements of each group had similar properties.
- 4Atomic numberThe number of protons in the nucleus of an element.
- 5Mendeleevs periodic lawWhen elements are arranged in order of increasing atomic weight the properties of the elements vary periodically.
- 6Modern Periodic lawWhen elements are arranged in order of increasing atomic number the properties of the elements vary periodically.
- 7Mass numberThe sum of the number of protons and neutron in the nucleus of an atom of the element.
- 8IsotopesAtoms of the same element with the same atomic number but different mass numbers due to different amounts of neutrons in the nucleus.
- 9Relative atomic massThe average of the masses of all the isotopes of an element, as they occur naturally, taking there abundance into account and based on a scale where a C-12 atom has a mass of 12 units.
- 10Alfabau principleWhen building up the electronic configuration of an element in it's ground state, the electrons occupy the lowest energy level available.
- 11Hunds rule of maximum mulplicityWhen two or more orbits of equal energy level are available electrons occupy then singly before filling them in pairs
- 12Pauli exclusion principleNo more then two electrons can occupy an orbital and they must have opposite spin.
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- leaving cert chemistry (Periodic table) FlashCards sobre definitions, criado por alannahsmyth305 em 31-05-2014.
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- alannahsmyth305
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