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Introduction to Atoms
Organizing the elements
Vocabulary
100
what is the smallest particle that can still be considered an element?
atom
100
What is atomic mass?
The average mass of all the isotopes of that element.
100
the basic part particle from which all elements are made?
atom
200
Who discovered that atoms contain negatively charged particles called electrons?
J.J Thomson
200
What did Mendeleev noticed when he arranged the elements in order?
He noticed a pattern of properties appeared.
200
what is a proton?
small postively charged particles that are found in the nucleus of an atom.
300
What object was in the center of the atom that had protons and neutrons?
Nucleus
300
What is the Periodic Table?
Arrangement of elements showing the repeating pattern of their properties.
300
what is period?
a horizontal row of elements in the periodic table.
400
What is atomic number?
The number of protons in the nucleus of an atom of that atom's elements.
400
Who created the first periodic table?
Mendeleev
500
How can you determine an atom's mass number?
The sum of the protons and neutrons in the atom
500
How are modern periodic tables arranged?
in order of increasing atomic number