Fichas
Atomic Structure and Isotopes
Fichas del conjunto (10)
- 1What is an isotopeAtoms of the same element that have different masses. The isotopes have the same number of protons and electrons, but different numbers of neutrons
- 2Relative Isotopic MassIs the mass of an atom of an isotope of an element compared with 1/12 the mass of carbon-12 which is taken as exactly 12
- 3Relative atomic massThe weighted mean mass of a molecule of an atom of an element compared with 1/12 of carbon-12 which is taken as exactly 12
- 4Relative Formula massIs the weighted mass of a formula unit of the compound compared with 1/12 of an atom of carbon-12 which is taken as exactly 12
- 5Use of mass spectroscopyIt only analyses positives ions but can be used to determine the isotopes in an element. It can also be used to analyse compounds with an accuracy of 4 decimal places.
Divide the abundance times the mass by the total abundances - 6Plum pudding model1897 JJ Thompson showed that atoms must contain smaller negatively charged particles, he assumed that there was a cloud of positive charge with these inside
- 7RutherfordRutherford and his students in 1909 fired alpha particles at thin sheets of gold foil, he drew the following conclusions:
Most of the atom is empty space hence how most particles passed through
There is a tiny positively charged nucleus where most of the mass is
It is surrounded by a cloud of negative charge - 8Bohr modelHe concluded - Electrons exist in fixed orbitals or shells, each of which has a fixed energy
When electrons move between shells radiation is emitted or absorbed
Radiation of this type will have a fixed frequency - 9Atomic radiiAs the electron shell fills up down a period the nuclear charge increases causing the electrons to be pulled in a bit more meaning atomic radii increases down a period
- 10Why do isotopes have the same chemical propertiesSame outer shell electron configuration
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- A-Level (2.1) Chemistry Fichas sobre Atomic Structure and Isotopes , creado por Reuben Veysey-Smith el 18/11/2015.
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- Reuben Veysey-Smith
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