Atoms, Elements, Compounds, and Ions
• Atom
• basic building block of all matter
• Element
•Substance that consists of only one type of atom.
•Molecule has two different atoms.
• Compound
• substance that consists of more than one type of
element.
• Ion
• substance that has a positive or negative charge
Atoms have:
• A nucleus
• small, heavy part of the atom
•An electron cloud
• large, lightweight part of the atom
Nucleus
Electron Cloud
Nucleus of an Atom
• Nucleus contains:
• Protons
• Have a positive charge
• All atoms are distinguished by
the number of protons it
has (atomic number)
• Neutrons
• Have no charge
• Have same mass as protons
N
N
N
Electron Cloud of an Atom
An electron cloud contains:
• Electrons
e-
• have a negative charge
e-
• are contained within shells of the
electron cloud
• orbit the nucleus of the atom
• have a very small mass compared to
protons and neutrons
• determine bonding properties of
substance
Atom Structure
Neutron
-1
Proton
Electron
+1
+1
-1
Elements
Elements contain one or more of the same type of atom!
Examples include:
Hydrogen – 1 proton per atom
Carbon
– 6 protons per atom
Oxygen – 8 protons per atom
Copper
– 29 protons per atom
Gold
– 79 protons per atom
Compounds contain more than one type of atom!
Example of organic compound (a compound with carbon atoms):
 Carbon Dioxide – CO2 (1 atom of carbon and two atoms of oxygen)
Example of inorganic compound (a compound with no carbon atoms):
 Water – H2O (2 atoms of hydrogen and one atom of oxygen)
-
+
An ion is an atom or group of atoms with a positive or negative
charge!!
 A particle with a neutral charge has the same number of
protons and electrons.
 An ion does not have the same number of electrons and protons.
 Examples of ions:
• He+ - A helium atom that is missing one electron.
The atom has one more proton than electron,
and must have a positive charge.
•CO32- - Carbonate has two more electrons than protons
Lets take a look deep
inside
Lets take a look deep
inside
Lets take a look deep
inside
Lets take a look deep
inside
This is a Proton.
Positive Charge
weighs ONE
Tells what type
of atom it is
GIRL
This is a Proton.
Positive Charge
weighs ONE
Tells what type
of atom it is
GIRL
This is a Proton.
Positive Charge
weighs ONE
Tells what type
of atom it is
GIRL
This is a Proton.
Positive Charge
weighs ONE
This is a Neutron No
Charge, Weighs One
NUN (does not
date)
Tells what type
of atom it is
GIRL
This is an Electron
No Weight
Negative charge
BOY
This is a Proton.
Positive Charge
weighs ONE
This is a Neutron No
Charge, Weighs ONE
NUN (does not
date)
Tells what type
of atom it is
GIRL
Element Guide
Element Guide
2
Element Guide
2
Element Guide
Proton Number-tells what
element it is. (also the
atomic number)
2
Element Guide
Proton Number-tells
what element it is. (also
the atomic number)
2
He
Element Guide
Proton Number-tells
what element it is. (also
the atomic number)
2
He
Element Guide
Proton Number-tells
what element it is. (also
the atomic number)
2
Explains name of the
element.
He
Element Guide
Proton Number-tells
what element it is. (also
the atomic number)
Explains name of the
element.
2
He
4
Element Guide
Proton Number-tells
what element it is. (also
the atomic number)
Explains name of the
element.
2
He
4
Element Guide
Proton Number-tells
what element it is. (also
the atomic number)
Explains name of the
element.
Explains the total
atomic weight-The
number of protons
PLUS the number of
neutrons.
2
He
4
Element Guide
Proton Number-tells
what element it is. (also
the atomic number)
Explains name of the
element.
Explains the total
atomic weight-The
number of protons
PLUS the number of
neutrons.
2
He
4