Photo of gold foil 2 atoms thick
Chapter 1A: Atoms, Elements,
and Molecules
Learning objectives
Define and identify: atoms, elements, ions, molecules, and
compounds.
Can you categorise the following as atoms,
elements, ions, molecules, and compounds?
What is an atom and element?
An atom is a neutral particle made of protons, neutrons, and
electrons.
An element is a substance that is made of one type of atom.
What are some examples of elements?
Oxygen
O2
Hydrogen
Sulfur
H2
S8
Chlorine Cl2
Neon Ne
Iron Fe
Diamond C
Ozone
O3
What is the difference between
molecule and compound?
A molecule is a particle
containing two or more atoms
covalently bonded together.
A compound is the same as a
molecule, except that the atoms
must be different elements.
Elements vs. compounds
Identify the following as either element or compound.
O2
He
C6H12O6
N2
NaCl
C60
Caffeine
What are ions?
An ion is a charged species made of one or more atoms
joined together.
Monatomic ions
Polyatomic ions
Learning objectives
Define and identify: atoms, elements, ions, molecules, and
compounds.
Can you categorise the following as atoms,
elements, ions, molecules, and compounds?
Species
Cu
Br2
NH4+
O3
CaO
H2O2
Xe
H+
Atom
Element Molecule Compound
Ion
Monoatomic Polyatomic