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Atomic Structure

demonstrate knowledge and understanding of how ideas about the atom changed over time, with reference to:
•    the Plum Pudding model;
•    Rutherford's model of a nucleus surrounded by electrons; and
•    the discovery of the neutron by Chadwick, leading to toda/s model of an atom;
describe the structure of an atom as a central positively charged nucleus containing protons and neutrons (most of the mass) surrounded by orbiting electrons in shells;

define mass number as the total number of protons and neutrons in an atom;
demonstrate knowledge and understanding that an atom as a whole has no electrical charge because the number of protons is equal to the number of electrons;
calculate the number of protons, neutrons and electrons in an atom or an ion and deduce the charge on an ion or determine the number of subatomic particles given the charge;

write and draw the electronic configuration (structure) of atoms and ions with atomic number 1-20;

recall that atoms have a radius of about 0.1 nmand that the nucleus is less than 1/10 000 of that of the atom 

define isotopes as atoms of an element with the same atomic number but a different mass number, indicating a different number of neutrons;.

interpret data on the number of protons, neutrons and electrons to identify isotopes of an element;

 calculate the relative atomic mass of elements from the mass number and abundances of its isotopes;l recall that a compound is two or more elements chemically combined;

 define isotopes as atoms of an element with the same atomic number but a different mass number, indicating a different number of neutrons;. interpret data on the number of protons, neutrons and electrons to identify isotopes of an element;! calculate the relative atomic mass of elements from the mass number and abundances of its isotopes;l recall that a compound is two or more elements chemically combined;

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