Download Atomic Structure - Northwest ISD Moodle

Basic Atomic Structure
Basic Atomic Structure
 Electrons have a charge of -1 and orbit the
nucleus.
 Protons have a charge of +1 and are located
in the nucleus with neutrons.
 Both are 1,840 times larger than electrons.
Atomic Number
 The atomic number is equal to the amount
of protons for an elemental atom.
 Atomic number or protons determine the type
of element that is present.
 In a neutral atom, the number of protons will
equal the amount of electrons.
Atomic Mass
 Mass number is the total number of protons and
neutrons in an atom.
 Mass Number = protons + neutrons
 Mass number - protons = Number of neutrons
Isotopes
 Isotopes are atoms of the same element that have a
different number of neutrons.
 Some isotopes are radioactive due to instability.
 The number of neutrons determines the isotope.
WRITING ISOTOPE NOTATION
 Practice Problems:
 How many protons, neutrons, and electrons in
Oxygen-16
 How many protons, neutrons, and electrons in
Oxygen-17
 Write the name for the isotope 40K.
 Write the name for the isotope 235U.
Ions – Atomic Structure
 Ions are created when
an atom has a different
number of protons and
electrons.
 Examples:
 Lithium: P-3, E-2
 Charge is +1
 Electrons can be gained
and lost by atoms.
 Ionic charges are
positive when there are
more protons and
negative when there are
more electrons.
 The number is the
difference of protons
and electrons.
 Fluorine: P-9, E-10
 Charge is -1