Studied by 2 people
groups
vertical columns
periods
horizontal rows
atomic mass
the mass of an atom. measured in AMU (atomic mass units)
atomic number
the number of protons in an atom
elements in the same group have ---because they have ---
similar properties, same number of valence electrons
elements are arranged by --- atomic numbers going across the table
increasing
T/F: The number of protons can change during a chemical or physical change
false
atomic mass
the average amount of protons and neutrons in an atom
how many known elements are there?
118
elements with an atomic number of more than -- are produced in laboratories and aren’t found naturally in earth
92
isotopes
atoms in an element that have different amounts of neutrons
ions
when an atomic gains or loses (an) electron(s)
ions have different --- than their original atom
chemical properties
where are metals on the periodic table?
the left
where are metalloids on the periodic table?
the stairstep
where are nonmetals on the periodic table?
the right
metallic properties --- from left to right
decrease
metallic properties --- from top to bottom
increase
what determines the chemical reactivity of an element?
the number of valence electrons
what are the 3 categories that elements can be?
metals, metalloids, and nonmetals
Note 
Flashcard (24)