Useful definitions in the periodic table

Question	Answer
Atomic Number	The number of protons in the nucleus of an atom
Element	A substance which can't be broken down into simpler materials by chemical means
Periodic Law	When elements are arranged by increasing atomic number, the properties vary periodically
Mass Number	The sum of protons and neutrons in the nucleus of an atom of that element
Isotope	Atoms of the same element that have a different number of neutrons in the nucleus
Relative Atomic Mass	The average mass of an atom of the element relative to one-twelfth the mass of a Carbon-12 atom
Triads	3 elements with similar chemical properties with the atomic weight of the middle element = the average of the other 2
Law of Octaves	Groups of elements arranged by atomic weight, in which similar properties occur after each interval of seven elements.

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	Created by eoin.examtime over 10 years ago

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