atoms
the smallest unit of an element that retains the chemical properties of that element
atom
a chart that provides information about all of the elements that are known to exist
periodic table of the elements
the element with an atomic number of 1
hydrogen
A _______ occurs when the chemical make-up or composition of a substance changes as a result of a chemical reaction.
chemical change
the last group of the periodic table
noble gases
an atomic particle with no charge
neutron
a horizontal row on the periodic table
period
the element with the symbol Na
Sodium
a series of symbols and formulas that represents a chemical reaction
chemical equation
the most reactive metals
alkali metals
the smallest unit of a compound that still retains the properties of that compound
molecule
a horizontal row beginning with lanthanum or actinium
series
a metal that crystallizes and changes colors when it cools slowly
bismuth
a scientific principle that states mass cannot be created or destroyed during ordinary physical or chemical changes
law of conservation of mass
column 3-12 on the periodic table
transition metals
the atomic particle(s) found inside the nucleus of an atom.
protons and neutrons
Elements with similar chemical properties are usually found in the same _______ of the periodic table.
group
the heaviest known element
oganesson
a substance that is transformed during a chemical reaction
reactant
the elements around the stairstep excluding aluminum and astatine
metalloids
positively charged atomic particle
proton
elements along the stairstep in the periodic table that have properties of both metals and nonmetals
metalloids
the element with the atomic number 19 on the periodic table
potassium
a substance that is created during a chemical reaction
product
the group including neodymium
lanthanides