What is the mass number of an atom?
The total number of protons and neutrons in its nucleus.
AQA GCSE Combined Science: Trilogy (8464) — Physics — Foundation · 6.4.1.2
Revise AQA GCSE Combined Science: Trilogy (8464) — Physics — Foundation specification point 6.4.1.2, Mass number, atomic number and isotopes, with free active-recall flashcards. Flip through the set or review every question and answer below.
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What is the mass number of an atom?
The total number of protons and neutrons in its nucleus.
Why do protons and neutrons account for nearly all of an atom’s mass?
They are the heavy particles in the nucleus.
What is the atomic number of an atom?
The number of protons in its nucleus.
What does an atom’s atomic number identify?
Its element.
Where are the mass number and atomic number placed in nuclide notation?
The mass number is at the top left of the chemical symbol; the atomic number is at the bottom left.
What are isotopes?
Atoms of the same element with the same number of protons but different numbers of neutrons.
Why do isotopes of the same element have different nucleon numbers?
They have different numbers of neutrons, while their proton numbers are the same.