Loading…
Loading…
GCSE Chemistry · key term
Atoms of the same element with the same number of protons but different numbers of neutrons.
Used by AQA, Edexcel and OCR
Specification 4.1.1.6 · Paper 1
Revise: Relative Atomic MassEvery atom of an element has the same number of protons, but its atoms can contain different numbers of neutrons. These different forms are isotopes. Because their numbers of neutrons differ, the isotopes have different mass numbers.
Specification 1.11 · Paper 1, Paper 2
Atoms of the same element that have the same number of protons but different numbers of neutrons.
Revise: Relative Atomic MassesAtoms of the same element with different numbers of neutrons are called isotopes. Different neutron numbers give the isotopes different masses. Their chemical identity remains the same because their proton number has not changed.
Paper 1 (Foundation), Paper 2 (Foundation), Paper 3 (Higher), Paper 4 (Higher)
Revise: Support for Mendeleev's ideasMost elements occur as mixtures of isotopes, whose atoms have the same number of protons but different numbers of neutrons. Relative atomic mass is a weighted mean that depends on the masses and natural abundances of those isotopes.
Atoms of the same element that have the same number of protons but different numbers of neutrons.
Do not find an ordinary mean of the isotope mass numbers unless the isotopes are equally abundant.
Multiply each isotope's mass number by its own percentage abundance before adding the products.
Your answer should lie between the smallest and largest isotope mass numbers and be closer to the mass number of the more abundant isotope.
Create a free account to read GCSE Chemistry revision notes for your exam board and track your progress.