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23 terms

Atomic structure, Isotopes, Ions, Periodic table

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Chemistry
The study of matter
Matter
Substance that has mass and occupies space. Made up of atoms.
Substance
Any material all samples of which have the same composition and properties (a mixture is not a substance).
Atom
The smallest unit of an element that still retains the properties of that element. Contains 3 subatomic particles: (Protons, Neutrons, Electrons)
Protons
Carries a positive charge and are found in the nucleus of an atom. ( the atomic number in the nucleus.)
Neutrons
Are neutral and are also found in the nucleus. The number of electrons in an atom must equal the number of protons. To find the number of neutrons in an atom subtract the atomic number from the mass number in an element.
Electrons
Carries a negative charge and are found outside the nucleus and arranged according th their energy level.
Element
Identified by its symbol and it's atomic number.
Atomic Number
Is equal to the number of protons found in the nucleus of each of its atoms.
Mass Number
The number of protons + neutrons found in the nucleus of an atom.
Isotope
Atoms of the same element (with the same number of protons) that contain a different number of neutrons, (atoms of the same element that have different numbers of neutrons)
Atomic Mass
total mass of the protons and neutrons in an atom, measured in atomic mass units
Ion
atom that has a positive or negative charge
Cation
an ion with a positive charge produced by the loss of one or more electrons
Anion
an ion that has a negative charge; forms when valence electrons are added to the outer energy level, giving the ion a stable electron configuration
Valence electron
an electron in the outer shell of an atom which can combine with other atoms to form molecules
Metalloid
an element that has some characteristics of metals and some characteristics of nonmetals
Noble Gas
one of the elements of Group 18 of the periodic table (helium, neon, argon, krypton, xenon, and radon); noble gases are unreactive
Period
a horizontal row of elements in the periodic table
Group
(chemistry) two or more atoms bound together as a single unit and forming part of a molecule
Metal
any of several chemical elements that are usually shiny solids that conduct heat or electricity and can be formed into sheets etc.
Radio isotope
An isotope that has an unstable nucleus and undergoes radioactive decay., An atom with normal number of neutrons that spontaneously breaks down releasing particles and energy
Nonmetal
a chemical element lacking typical metallic properties., an element that conducts heat and electricity poorly.