These are pure substances from which all other things are built
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Periodic Table
The arrangement of 118 elements
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Period
Each horizontal row in the periodic table
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Group
Each vertical column on the periodic table
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Representative Elements
These have group numbers 1A to 8A
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Transition Elements
These are block elements in the center of a periodic table that have group numbers followed by the letter ‘B
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Group 1A
These are alkali metals except for Hydrogen
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Group 2A
These are alkaline earth metals; these are shiny metals but not as reactive
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Group 7A
These are halogens; highly reactive and form compounds with most of the elements
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Group 8A
These are noble gases; they are quite unreactive and are seldom found in combination with other elements
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lanthanides and actinides
The two rows of 14 elements called the ______, which are part of Periods 6 and 7, are placed at the bottom of the periodic table to allow them to fit on a page.
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Metals
These are shiny solids, such as copper, gold, and silver
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Nonmetals
They are often poor conductors of heat and electricity
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Metalloids
These are elements that exhibit some properties that are typical of metals and other properties that are characteristic of nonmetals
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Atom
The smallest unit particle of an element that retains the characteristics of that element
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Subatomic Particles
These are even smaller bits of matter
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Cathode Rays
These are streams of small particles produced when electricity is applied to a glass tube
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Protons
These are the atoms positively charged particles
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Electrons
These are the atoms negatively charged particles
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Neutrons
These are the atoms neutral particles
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Nucleus
The center of the atom
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Atomic Mass Unit
A very small unit of mass
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Dalton
The atomic mass unit
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Atomic Number
This is equal to the number of protons in every atom of that element
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Mass Numer
The total number of protons and neutrons in its nucleus
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Number of neutrons in a nucleus = mass number
number of protons
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Isotopes
These are atoms of the same element that have the same atomic number but different numbers of neutrons
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weighted average
Because each isotope has a different mass, chemists have calculated an atomic mass for an “average atom,” which is a ______ of the masses of all the naturally occurring isotopes of that element.
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Atomic Symbol
It indicates the mass number in the upper left corner and the atomic number in the lower left corner
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Electromagnetic spectrum
It shows the arrangement of different types of electromagnetic radiation in order of increasing energy
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atomic spectrum
When light from a heated element passes through a prism, it separates into distinct lines of color separated by dark areas called an _____.
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principal quantum numbers
In an atom, each electron has a specific energy known as its energy level, which is assigned values called _____.
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electron arrangement
The ______ of an atom gives the number of electrons in each energy level.
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Period Properties
These consists of the valence electrons in atoms, the trends in atomic size, ionization energy, and metallic character
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Valence Electrons
These are the electrons in the outermost energy level
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Electron-Dot Symbol
Also known as a Lewis Structure, represents the valence electrons as dots that are placed on the sides, top, or bottom of the symbol for the element
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Ionization Energy
A quantity of energy that is required to remove one of the outermost electrons
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Cation
A positive particle
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Anion
A negative particle.
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Metallic Character
An element that loses valence electrons easily
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According to Dalton’s Atomic Theory,
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atoms
According to Dalton’s Atomic Theory, All matter is made up of tiny particles called ______.
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similar to one another and different from atoms of other elements
According to Dalton’s Atomic Theory, All atoms of a given element are ______________.
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compounds
According to Dalton’s Atomic Theory, Atoms of two or more different elements combine to form _______.
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chemical reaction
According to Dalton’s Atomic Theory, Atoms are never created or destroyed during a ________.