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Atoms and isotopes key terms
Study Atoms and isotopes with curriculum-aligned Key Terms resources, practice links, and exam-focused support.
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key terms
Resource type
Topic
Atoms and isotopes
Key terms
isotope
Atoms of the same element that have different numbers of neutrons.
atomic number
The number of protons in the nucleus of an atom, which determines the element.
isotope
Atoms of the same element with different numbers of neutrons.
mass number
The total number of protons and neutrons in the nucleus of an atom.
isotope
Atoms of the same element with different numbers of neutrons.
chemical properties
Characteristics of a substance that determine how it interacts with other substances.
isotope
Atoms of the same element that have different numbers of neutrons.
mass number
The total number of protons and neutrons in the nucleus of an atom.
isotope
Atoms of the same element that have different numbers of neutrons.
mass number
The total number of protons and neutrons in the nucleus of an atom.
radioactive isotope
An isotope with an unstable nucleus that can emit radiation.
isotope
Atoms of the same element that have different numbers of neutrons.
unstable nucleus
A nucleus that has an imbalance of protons and neutrons, leading to the emission of radiation to achieve stability.
radiation emission
The process by which unstable nuclei release energy in the form of particles or electromagnetic waves to become more stable.
indivisible sphere
The early model of the atom proposed that it is a tiny, solid, and indivisible particle.
plum pudding model
A historical model of the atom where negative electrons are embedded within a positively charged 'soup' of charge.
plum pudding model
An early model of the atom where negative electrons are embedded in a positively charged 'soup'.
electron
A negatively charged subatomic particle found in shells around the nucleus of an atom.
plum pudding model
A historical model of the atom where negative electrons are embedded in a positively charged sphere.
nuclear model
A model of the atom that describes a small, dense nucleus containing protons and neutrons, with electrons orbiting around it.
alpha particle scattering
An experiment that demonstrated the presence of a small, dense nucleus in an atom by observing the deflection of alpha particles when they pass through a thin gold foil.
nuclear model
A model of the atom proposed by Rutherford, which describes the atom as having a small, positively charged nucleus surrounded by electrons.
alpha particle scattering
An experiment demonstrating that most alpha particles pass through gold foil, indicating that atoms are mostly empty space.
nuclear model
The model of the atom that describes a small, dense nucleus containing protons and neutrons, with electrons orbiting around it.
alpha particle
A positively charged particle consisting of two protons and two neutrons, emitted during radioactive decay.
nucleus
The small, dense central part of an atom that contains protons and neutrons.
alpha particle
A positively charged particle consisting of two protons and two neutrons, emitted during radioactive decay.
nuclear model
A model of the atom that describes it as having a small, dense nucleus containing protons and neutrons, with electrons orbiting around it.
plum pudding model
An early model of the atom proposed by J.J. Thomson, depicting it as a sphere of positive charge with negatively charged electrons embedded within.
nuclear model
The atomic model developed by Ernest Rutherford, which describes the atom as having a small, dense nucleus containing protons and neutrons, with electrons orbiting around it.
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