Download L1 - Atom

ATOM
PROTONS
Charge: positive
Mass:
1 amu
Location: nucleus
ELECTRONS
Charge: negative
Mass:
zero
Location: electron
cloud
NEUTRONS
Charge: none
Mass:
1 amu
Location: nucleus
NUCLEUS is the small, positively
charged
Center of the atom. It has most of the
atom’s mass.
The mass of an atom is so small, scientist
made a new SI unit, atomic mass unit
(amu).
In an atom, the numbers of protons and
electrons are the same, so their charges cancel
out. An atom
has no overall electric charge, it is neutral.
How can you tell which elements different
atoms represent? The key is the number of
protons. The number of protons in the nucleus
of an atom is the atomic number of that atom.
The mass number is the total number of protons
and neutrons in an atom.
Subtract the atomic number from the atomic mass
to find out the number of neutrons.
Locate Fluorine on the periodic table.
Mass: 19
Atomic Number 9
Protons: 9
Electrons: 9
Neutrons: 10
Mass Number (19)
-Atomic Number (9)
Neutrons (10)
Look at the Periodic Table, locate the following
elements using their atomic number: carbon,
potassium, gold.
How many protons does Carbon have? 6
How many electrons does Potassium have? 19
How many neutrons does Gold have? 118