Atoms
All elements are made up of atoms.
Atoms are the basic particles of all
matter
Atoms
• An atom of Oxygen for example, is the
smallest amount of oxygen you can possibly
have
• Atoms of elements contain protons, neutrons
and electrons
Charges and Location
• Protons= positive charge/inside nucleus
• Neutrons= neutral (no) charge/inside nucleus
• Electrons= negative charge/outside nucleus in
an electron cloud
An Atom of Oxygen
Ions
• An ion is an atom that is either missing
electrons or has some extra electrons
• Example: When lithium ionically bonds with
bromine to form lithium bromide it gives up its
one valence electron (outermost electron) to
bromine leaving it with 2 electrons rather than
3. Bromine then has 36 electrons rather than
35.
Electrolytes
• Electrolytes form ions in water and can
conduct electricity
– Example: Carbonic acid breaks down into ions
when dissolved in water
H2CO3
H+ + HCO3-