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Defining isotopes using subatomic particles
Chadwick’s experiments showed the existence of neutrons in an atom. This led to an understanding of isotopes.
Define the term ‘isotopes’. Refer to subatomic particles in your answer.
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Marking points
- 1 States that isotope atoms have the same number of protons or atomic number.
- 2 States that they have different numbers of neutrons.
Full-mark answer
Isotopes are atoms of the same element with the same number of protons but different numbers of neutrons.
Why this answer loses marks
Isotopes are atoms with different numbers of electrons.
Electrons do not define isotopes; match the proton number and vary the neutron number.