Periodic Table
The first periodic table was arranged by
atomic mass
Most _________ are ductile, malleable, and good conductors of heat and electricity
metals
particles in an atom that have an negative charge
each element has a ______ that consists of one or two letters, the first is capital.
symbol
the ______ is the very small center core of an atom
nucleus
the periodic table is now arranged by
atomic number
This group contains the most elements
transition metals
the outer energy level of an atom can hold a maximum of ____ electrons (except hydrogen and helium)
8
do not ordinarily form compounds
noble gases
What elements make up the stairs step/zig zag? What properties do they have?
metalloids - properties of both metals and nonmetals
Elements in a column of the periodic table
have similar properties
have the same number of valence electrons
The most reactive metals are in what group?
Group 1 - Alkali Metals
In an atom, the number of protons equals the number of
electrons
the two most common alkaline earth metals
calcium and magnesium
smaller particles that make up protons and neutrons
quarks
this number indicates the number of protons
Atomic number
which group reacts violently with group 1?
group 17
the maximum number of electrons the third level of an atom's electron cloud can hold is
18
include familiar metals such as gold, silver, copper, and nickel
transition metals
how do you find the number of neutrons in an atom?
Atomic Mass - Atomic Number
horizontal rows of the periodic table are
nonmetals are ______ conductors of heat and electricity
atoms of the same elements with different numbers of neutrons are called
isotopes
halogens
part of ______ atomic theory was "atoms cannot be created or destroyed in any chemical change, only rearranged."
Dalton's