Download Atoms and Elements

Atoms and Elements
Subatomic Particles
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Atom- Smallest particle of an element.
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Subatomic Particles- Atoms are composed of protons,
neutrons, and electrons.
Nucleus- Small dense positively charged center of an
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atom.
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Proton- Subatomic particle that has a positive charge
and is found in the nucleus of an atom.
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Electron- negatively charged subatomic particle found
in an area outside the nucleus of an atom.
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Neutron- Subatomic particle with no electric charge
that is found in the nucleus of an atom.
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Atoms have their
electrons arranged in
layers called shells
1st level- 2 electrons max.
2nd Level- 8 electrons max.
3rd level- 18 electrons max.
4th level- 32 electrons max.
Using the Periodic Table to
understand makeup of atoms
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Atomic Number- Number of
protons in the nucleus.
Atomic Mass- Average of the
masses of the existing isotopes
of an element.
Mass number- the sum of
the protons and neutrons in its
nucleus.