HOW DO YOU DETERMINE THE AMOUNT
OF SUBATOMIC PARTICLES IN AN ATOM?
IT BEGINS WITH THE PERIODIC TABLE
An arrangement of elements in which the
elements are separated based on properties
DISTINGUISHING ELEMENTS
The atomic number of every element
represents the number of protons in the
nucleus of an atom of that element.
MASS NUMBER
The total number of protons and neutrons in an
atom.
Number of neutrons = mass number – atomic number
Chemical Symbol Shorthand Notation
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WHAT ABOUT ELECTRONS?
Electrons in an atom are equal to the number
of protons.
FORCE OF THE NUCLEUS
The nucleus is made of p + n
2 protons are close together there is a strong
attraction
Nuclear
Force
ISOTOPES
Atoms (of the same element) that have the
same number of protons but a different
number of neutrons.
Do Isotopes have different mass numbers?
COMMON ISOTOPES
Hydrogen
Hydrogen-1
(Hydrogen)
Hydrogen-2 (Deuterium)
Used
as a moderator in nuclear reactors
Hydrogen-3
Used
(Tritium)
in the production of Hydrogen bombs
PRACTICE!
There are 3 isotopes of Oxygen. Oxygen-16,
Oxygen-17 and Oxygen 18. Write each in
shorthand notation.
There are 3 isotopes of Chromium. Chromium50, Chromium-52 and Chromium-53. How
many neutrons are in each isotope?
ATOMIC MASS UNITS
One twelfth of the mass of a carbon-12 atom
IF THERE ARE ISOTOPES HOW DO YOU
CALCULATE 1 ATOMIC MASS?
Calculate a weighted average
Not
You
each isotope is as common as the next
need to know the mass of each isotope and its
natural abundance.
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