Ions and Isotopes
Changing Atoms Without Changing Elements
Ions
An ion is an atom or group of atoms with a net electric charge because it has gained or lost electrons.
Isotopes
Isotopes are atoms of the same element with different numbers of neutrons. They have the same number of protons but different masses.
Key Ideas
Remember
Changing electrons makes an ion. Changing neutrons makes an isotope. Changing protons makes a different element.
What happens when an atom loses an electron?
Losing a negatively charged electron leaves a net positive charge.
Correct answer: It becomes a positive ion
What do we call atoms of the same element with different numbers of neutrons?
Isotopes are variants of an element that differ in neutron number.
Correct answer: isotopes
If two atoms have the same number of protons but different numbers of neutrons, they are different
Same element, different neutrons means isotopes.
Correct answer: isotopes
How to Tell Them Apart
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1
Check the number of protons to identify the element.
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2
Check the number of electrons to see if the atom is charged.
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3
Check the number of neutrons to distinguish isotopes.
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4
Combine the information to describe the atom fully.
What changes when an atom becomes an ion?
Ions form by gaining or losing electrons.
Correct answer: Number of electrons