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the smallest particle into which an element can be divided and still be the same element.
What is an atom?
negatively charged particles
What is an electron?
the small dense center of an atom that has a positive charge
What is the nucleus?
positively charged particles
What is a proton?
uncharged particles
What is a neutron?
the number of protons in an atom
What is the atomic number?
the total number of protons and neutrons in an atom's nucleus
What is the mass number?
an abbreviation for the element's name
What is the chemical symbol?
each vertical column on the periodic table
What is a group?
each horizontal row of elements on the periodic table
What is a period?
elements that are shiny and conduct electricity well
What is a metal?
poor conductors of heat and electricity and are often dull and brittle
What is a nonmetal?
elements that have some properties of metals and nonmetals
What is a metalloid?
electrons move within this area around a nucleus
What is the electron cloud?
the substances that participate in a chemical reaction
What are the reactants?
the substances formed in a chemical reaction
What are the products?
a chemical reaction that requires an input of heat
What is an endothermic reaction?
a chemical reaction in which energy is released to the surroundings
What is an exothermic reaction?
the process in which atoms are rearranged to produce new substances
What is a chemical reaction?
uses chemical symbols and numbers to represent a given substance
What is a chemical formula?
an expression that uses symbols to show the relationship between the starting substance and the substances that are produced by a chemical reaction
What is a chemical equation?
a table of the chemical elements arranged in order of atomic number
What is the periodic table?